ARM: sunxi: hackberry: Add UART muxing

We previously relied on the bootloader to do the muxing of the UART for
the Hackberry. Don't rely on it anymore and use pinctrl.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Emilio López <emilio@elopez.com.ar>

arch/arm/boot/dts/sun4i-a10-hackberry.dts

@@ -24,6 +24,8 @@
 
 	soc {
 		uart0: serial@01c28000 {
+			pinctrl-names = "default";
+			pinctrl-0 = <&uart0_pins_a>;
 			status = "okay";
 		};
 	};