suniv: add UART1 support

Some boards with the Allwinner F1C100s family SoCs use UART1 for its
debug UART, so define the pins for the SPL and the pinmux name and mux
value for U-Boot proper.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
index 9ce2bc1..061104b 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
@@ -245,6 +245,7 @@
 #else
 	{ "uart0",	5 },	/* PE0-PE1 */
 #endif
+	{ "uart1",	5 },	/* PA0-PA3 */
 };
 
 static const struct sunxi_pinctrl_desc __maybe_unused suniv_f1c100s_pinctrl_desc = {