ARM: dts: sun6i: Add mmc2_pins_a pinmux setting to sun6i-a31.dtsi

Add a pinmux setting for using mmc2 in regular 4 bit mode.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun6i-a31.dtsi

@@ -691,7 +691,15 @@
 				allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
 			};
 
-			mmc2_8bit_emmc_pins: mmc2@0 {
+			mmc2_pins_a: mmc2@0 {
+				allwinner,pins = "PC6", "PC7", "PC8", "PC9",
+						 "PC10", "PC11";
+				allwinner,function = "mmc2";
+				allwinner,drive = <SUN4I_PINCTRL_30_MA>;
+				allwinner,pull = <SUN4I_PINCTRL_PULL_UP>;
+			};
+
+			mmc2_8bit_emmc_pins: mmc2@1 {
 				allwinner,pins = "PC6", "PC7", "PC8", "PC9",
 						 "PC10", "PC11", "PC12",
 						 "PC13", "PC14", "PC15",