ARM: dts: imx: replace legacy wakeup property with 'wakeup-source'

Though the keyboard and other driver will continue to support the legacy
"gpio-key,wakeup", "linux,wakeup" and "enable-sdio-wakeup" boolean
property to enable the wakeup source, "wakeup-source" is the new
standard binding.

This patch replaces all the legacy wakeup properties with the unified
"wakeup-source" property in order to avoid any futher copy-paste
duplication.

Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
diff --git a/arch/arm/boot/dts/imx7d-sdb.dts b/arch/arm/boot/dts/imx7d-sdb.dts
index b2c4536..b267f79 100644
--- a/arch/arm/boot/dts/imx7d-sdb.dts
+++ b/arch/arm/boot/dts/imx7d-sdb.dts
@@ -296,7 +296,7 @@
 	pinctrl-0 = <&pinctrl_usdhc1>;
 	cd-gpios = <&gpio5 0 GPIO_ACTIVE_LOW>;
 	wp-gpios = <&gpio5 1 GPIO_ACTIVE_HIGH>;
-	enable-sdio-wakeup;
+	wakeup-source;
 	keep-power-in-suspend;
 	status = "okay";
 };