ARM: dts: Replace legacy *,wakeup property with wakeup-source for exynos boards

Though the keyboard and other driver will continue to support the legacy
"gpio-key,wakeup", "linux-keypad,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 further copy-paste
duplication.

Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

arch/arm/boot/dts/exynos5420-peach-pit.dts

@@ -65,7 +65,7 @@
 			label = "Power";
 			gpios = <&gpx1 2 GPIO_ACTIVE_LOW>;
 			linux,code = <KEY_POWER>;
-			gpio-key,wakeup;
+			wakeup-source;
 		};
 
 		lid-switch {
@@ -74,7 +74,7 @@
 			linux,input-type = <5>; /* EV_SW */
 			linux,code = <0>; /* SW_LID */
 			debounce-interval = <1>;
-			gpio-key,wakeup;
+			wakeup-source;
 		};
 	};