ARM: dts: AM33XX: Add push-buttons device tree data to am335x-evmsk

Add gpio based push buttons device tree data to am335x-evmsk device
by adding all the necessary parameters like key-code, gpios and etc.
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Benoit Cousson <b-cousson@ti.com>

arch/arm/boot/dts/am335x-evmsk.dts

@@ -139,6 +139,37 @@ led@4 {
 			default-state = "off";
 		};
 	};
+
+	gpio_buttons: gpio_buttons@0 {
+		compatible = "gpio-keys";
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		switch@1 {
+			label = "button0";
+			linux,code = <0x100>;
+			gpios = <&gpio3 3 0>;
+		};
+
+		switch@2 {
+			label = "button1";
+			linux,code = <0x101>;
+			gpios = <&gpio3 2 0>;
+		};
+
+		switch@3 {
+			label = "button2";
+			linux,code = <0x102>;
+			gpios = <&gpio1 30 0>;
+			gpio-key,wakeup;
+		};
+
+		switch@4 {
+			label = "button3";
+			linux,code = <0x103>;
+			gpios = <&gpio3 5 0>;
+		};
+	};
 };
 
 /include/ "tps65910.dtsi"