arm64: dts: mediatek: mt8183-pumpkin: add keypad support

Add device-tree bindings for the keypad driver on the MT8183 Pumpkin
board.

The MT8183 Pumpkin board has 2 buttons connected using: KPROW0,
KPROW1 and KPCOL0.
Signed-off-by: Fabien Parent <fparent@baylibre.com>
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20220720-mt8183-keypad-v2-7-6d42c357cb76@baylibre.comSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>

arch/arm64/boot/dts/mediatek/mt8183-pumpkin.dts

@@ -7,6 +7,7 @@
 /dts-v1/;
 
 #include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
 #include "mt8183.dtsi"
 #include "mt6358.dtsi"
 
@@ -122,6 +123,18 @@ &i2c6 {
 	clock-frequency = <100000>;
 };
 
+&keyboard {
+	pinctrl-names = "default";
+	pinctrl-0 = <&keyboard_pins>;
+	status = "okay";
+	linux,keymap = <MATRIX_KEY(0x00, 0x00, KEY_VOLUMEDOWN)
+			MATRIX_KEY(0x01, 0x00, KEY_VOLUMEUP)>;
+	keypad,num-rows = <2>;
+	keypad,num-columns = <1>;
+	debounce-delay-ms = <32>;
+	mediatek,keys-per-group = <2>;
+};
+
 &mmc0 {
 	status = "okay";
 	pinctrl-names = "default", "state_uhs";
@@ -226,6 +239,14 @@ pins_cmd_dat {
 		};
 	};
 
+	keyboard_pins: keyboard {
+		pins_keyboard {
+			pinmux = <PINMUX_GPIO91__FUNC_KPROW1>,
+				 <PINMUX_GPIO92__FUNC_KPROW0>,
+				 <PINMUX_GPIO93__FUNC_KPCOL0>;
+		};
+	};
+
 	mmc0_pins_default: mmc0-pins-default {
 		pins_cmd_dat {
 			pinmux = <PINMUX_GPIO123__FUNC_MSDC0_DAT0>,