ramips: fix DCH-M225 support

Setting the pins of the UARTF group to GPIO+I2S at the time the I2C
driver loads is to late for the wps GPIO button.

The gpio-keys driver fails to load since the pin used by the wps button
is not yet set to GPIO. The wps button with the rfkill keycode is
essential for this wireless only board.

Add the missing sound and I2C kernel modules corresponding to the
device nodes.

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/ramips/dts/DCH-M225.dts

@@ -90,7 +90,7 @@
 	#sound-dai-cells = <0>;
 	status = "okay";
 	pinctrl-names = "default";
-	pinctrl-0 = <&gpio_i2s_pins>, <&wm8960_mclk_pins>;
+	pinctrl-0 = <&wm8960_mclk_pins>;
 };
 
 &spi0 {
@@ -158,6 +158,11 @@
 			ralink,function = "gpio";
 		};
 
+		gpio_i2s {
+			ralink,group = "uartf";
+			ralink,function = "gpio i2s";
+		};
+
 		pa {
 			ralink,group = "pa";
 			ralink,function = "pa";

target/linux/ramips/image/mt7620.mk

@@ -139,7 +139,7 @@ define Device/dch-m225
 	seama-seal -m "signature=wapn22_dlink.2013gui_dap1320b" | \
 	check-size $$$$(IMAGE_SIZE)
   DEVICE_TITLE := D-Link DCH-M225
-  DEVICE_PACKAGES := kmod-mt76
+  DEVICE_PACKAGES := kmod-mt76 kmod-sound-core kmod-sound-mt7620 kmod-i2c-ralink
 endef
 TARGET_DEVICES += dch-m225