ARM: dts: imx7d-sdb: add gpio key support

Add support for imx7d-sdb board's gpio keys:

S1(FUNC1): KEY_VOLUMEUP
S3(FUNC2): KEY_VOLUMEDOWN
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx7d-sdb.dts

@@ -52,6 +52,24 @@ memory@80000000 {
 		reg = <0x80000000 0x80000000>;
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_gpio_keys>;
+
+		volume-up {
+			label = "Volume Up";
+			gpios = <&gpio5 11 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_VOLUMEUP>;
+		};
+
+		volume-down {
+			label = "Volume Down";
+			gpios = <&gpio5 10 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_VOLUMEDOWN>;
+		};
+	};
+
 	spi4 {
 		compatible = "spi-gpio";
 		pinctrl-names = "default";
@@ -519,6 +537,12 @@ MX7D_PAD_EPDC_DATA14__GPIO2_IO14	0x59	/* CAN_STBY */
 			>;
 		};
 
+		pinctrl_gpio_keys: gpio_keysgrp {
+			fsl,pins = <
+				MX7D_PAD_SD2_RESET_B__GPIO5_IO11	0x59
+				MX7D_PAD_SD2_WP__GPIO5_IO10		0x59
+			>;
+		};
 
 		pinctrl_hog: hoggrp {
 			fsl,pins = <