boards: arm: wio terminal: separate buttons and joystick definition

The purpose of this separation is to avoid conflict initializing
gpio-keys because button 0 and joystick up have a shared interrupt
source. Buttons are now configured using polling mode option.

Signed-off-by: Joel Guittet <joelguittet@gmail.com>

boards/arm/wio_terminal/wio_terminal.dts

@@ -48,8 +48,10 @@
 	};
 
 	/* Buttons */
-	gpio_keys {
+	buttons {
 		compatible = "gpio-keys";
+		polling-mode;
+		debounce-interval-ms = <100>;
 		user_button_0: button_0 {
 			label = "User Button 0";
 			gpios = <&portc 26 GPIO_ACTIVE_LOW>;
@@ -65,6 +67,11 @@
 			gpios = <&portc 28 GPIO_ACTIVE_LOW>;
 			zephyr,code = <INPUT_KEY_2>;
 		};
+	};
+
+	/* Joystick */
+	joystick {
+		compatible = "gpio-keys";
 		joy_sel: joystick_selection {
 			label = "joystick selection";
 			gpios = <&portd 10 GPIO_ACTIVE_LOW>;