ARM: dts: am335x/am437x: remove unneeded unit name for gpio-matrix-keypad

This patch fixes the following DTC warnings for many boards:

"Node /matrix_keypad@0 has a unit name, but no reg property"

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/boot/dts/am437x-sk-evm.dts b/arch/arm/boot/dts/am437x-sk-evm.dts
index 5687d6b..9d71246 100644
--- a/arch/arm/boot/dts/am437x-sk-evm.dts
+++ b/arch/arm/boot/dts/am437x-sk-evm.dts
@@ -64,7 +64,7 @@
 		};
 	};
 
-	matrix_keypad: matrix_keypad@0 {
+	matrix_keypad: matrix_keypad0 {
 		compatible = "gpio-matrix-keypad";
 
 		pinctrl-names = "default";