ARM: dts: zynq: replace gpio-key,wakeup with wakeup-source property

Most of the legacy "gpio-key,wakeup" boolean property is already
replaced with "wakeup-source". However few occurrences of old property
has popped up again, probably from the remnants in downstream trees.

Replace the legacy properties with the unified "wakeup-source"
property introduced in the commit 700a38b2 ("Input: gpio_keys -
switch to using generic device properties")

Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/boot/dts/zynq-zturn.dts

@@ -54,7 +54,7 @@ K1 {
 			label = "K1";
 			gpios = <&gpio0 0x32 0x1>;
 			linux,code = <0x66>;
-			gpio-key,wakeup;
+			wakeup-source;
 			autorepeat;
 		};
 	};