ARM: dts: sun6i: sina31s: Switch to mmc3 for onboard eMMC

According to Allwinner, only mmc3 supports 8 bit DDR transfers for eMMC.
Switch to mmc3 for the onboard eMMC, and also assign vqmmc for signal
voltage sensing, and "cap-mmc-hw-reset" to denote this instance can use
eMMC hardware reset.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun6i-a31s-sina31s-core.dtsi

@@ -61,12 +61,14 @@ &cpu0 {
 };
 
 /* eMMC on core board */
-&mmc2 {
+&mmc3 {
 	pinctrl-names = "default";
-	pinctrl-0 = <&mmc2_8bit_emmc_pins>;
+	pinctrl-0 = <&mmc3_8bit_emmc_pins>;
 	vmmc-supply = <&reg_dcdc1>;
+	vqmmc-supply = <&reg_dcdc1>;
 	bus-width = <8>;
 	non-removable;
+	cap-mmc-hw-reset;
 	status = "okay";
 };