dt-bindings: Drop unnecessary *-supply schemas properties

*-supply properties are always a single phandle, so binding schemas
don't need a type $ref nor 'maxItems'.

A meta-schema check for this is pending once these existing cases are
fixed.

Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-iio@vger.kernel.org
Cc: linux-input@vger.kernel.org
Cc: linux-media@vger.kernel.org
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20201221234659.824881-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
diff --git a/Documentation/devicetree/bindings/display/bridge/anx6345.yaml b/Documentation/devicetree/bindings/display/bridge/anx6345.yaml
index 8c0e4f28..fccd635 100644
--- a/Documentation/devicetree/bindings/display/bridge/anx6345.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/anx6345.yaml
@@ -26,11 +26,9 @@
     description: GPIO connected to active low reset
 
   dvdd12-supply:
-    maxItems: 1
     description: Regulator for 1.2V digital core power.
 
   dvdd25-supply:
-    maxItems: 1
     description: Regulator for 2.5V digital core power.
 
   ports:
diff --git a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
index efbb3d0..02cfc0a 100644
--- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml
@@ -35,11 +35,9 @@
     maxItems: 1
 
   ovdd-supply:
-    maxItems: 1
     description: I/O voltage
 
   pwr18-supply:
-    maxItems: 1
     description: core voltage
 
   interrupts:
diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
index e5e3c72..66a14d6 100644
--- a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
@@ -79,8 +79,7 @@
       The GPIO used to control the power down line of this device.
     maxItems: 1
 
-  power-supply:
-    maxItems: 1
+  power-supply: true
 
 required:
   - compatible
diff --git a/Documentation/devicetree/bindings/display/bridge/ps8640.yaml b/Documentation/devicetree/bindings/display/bridge/ps8640.yaml
index 7e27cfc..763c790 100644
--- a/Documentation/devicetree/bindings/display/bridge/ps8640.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/ps8640.yaml
@@ -35,11 +35,9 @@
     description: GPIO connected to active low reset.
 
   vdd12-supply:
-    maxItems: 1
     description: Regulator for 1.2V digital core power.
 
   vdd33-supply:
-    maxItems: 1
     description: Regulator for 3.3V digital core power.
 
   ports:
diff --git a/Documentation/devicetree/bindings/display/bridge/simple-bridge.yaml b/Documentation/devicetree/bindings/display/bridge/simple-bridge.yaml
index 3ddb35f..64e8a1c 100644
--- a/Documentation/devicetree/bindings/display/bridge/simple-bridge.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/simple-bridge.yaml
@@ -60,7 +60,6 @@
     description: GPIO controlling bridge enable
 
   vdd-supply:
-    maxItems: 1
     description: Power supply for the bridge
 
 required:
diff --git a/Documentation/devicetree/bindings/display/bridge/thine,thc63lvd1024.yaml b/Documentation/devicetree/bindings/display/bridge/thine,thc63lvd1024.yaml
index 469ac4a..3d5ce08 100644
--- a/Documentation/devicetree/bindings/display/bridge/thine,thc63lvd1024.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/thine,thc63lvd1024.yaml
@@ -74,7 +74,6 @@
     description: Power down GPIO signal, pin name "/PDWN", active low.
 
   vcc-supply:
-    maxItems: 1
     description:
       Power supply for the TTL output, TTL CLOCKOUT signal, LVDS input, PLL and
       digital circuitry.
diff --git a/Documentation/devicetree/bindings/display/bridge/toshiba,tc358775.yaml b/Documentation/devicetree/bindings/display/bridge/toshiba,tc358775.yaml
index fd3113a..b5959cc 100644
--- a/Documentation/devicetree/bindings/display/bridge/toshiba,tc358775.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/toshiba,tc358775.yaml
@@ -28,11 +28,9 @@
     description: i2c address of the bridge, 0x0f
 
   vdd-supply:
-    maxItems: 1
     description: 1.2V LVDS Power Supply
 
   vddio-supply:
-    maxItems: 1
     description: 1.8V IO Power Supply
 
   stby-gpios: