pinctrl: sunxi: add Allwinner D1 pinctrl description

Apart from using the new pinctrl MMIO register layout, the Allwinner D1
and related SoCs still need to usual set of mux values hardcoded in
U-Boot's pinctrl driver.
Add the values we need so far to this list, so that DM based drivers
will just work without further ado.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/drivers/pinctrl/sunxi/Kconfig b/drivers/pinctrl/sunxi/Kconfig
index 77da908..c8f937d 100644
--- a/drivers/pinctrl/sunxi/Kconfig
+++ b/drivers/pinctrl/sunxi/Kconfig
@@ -124,4 +124,8 @@
 	default MACH_SUN50I_H616
 	select PINCTRL_SUNXI
 
+config PINCTRL_SUN20I_D1
+	bool "Support for the Allwinner D1/R528 PIO"
+	select PINCTRL_SUNXI
+
 endif