pinctrl: uniphier: support pin configuration

Support the following DT properties:
  "bias-disable"
  "bias-pull-up"
  "bias-pull-down"
  "bias-pull-pin-default"
  "input-enable"
  "input-disable"

My main motivation is to support pull up/down biasing.  For Pro5 and
later SoCs, the pupdctrl register number is the same as the pinmux
number, so this feature can be supported without having big pin
tables.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/pinctrl/uniphier/pinctrl-uniphier-ld20.c b/drivers/pinctrl/uniphier/pinctrl-uniphier-ld20.c
index 0c46450..5a7d142 100644
--- a/drivers/pinctrl/uniphier/pinctrl-uniphier-ld20.c
+++ b/drivers/pinctrl/uniphier/pinctrl-uniphier-ld20.c
@@ -106,7 +106,8 @@
 	.groups_count = ARRAY_SIZE(uniphier_ld20_groups),
 	.functions = uniphier_ld20_functions,
 	.functions_count = ARRAY_SIZE(uniphier_ld20_functions),
-	.caps = UNIPHIER_PINCTRL_CAPS_PERPIN_IECTRL,
+	.caps = UNIPHIER_PINCTRL_CAPS_PUPD_SIMPLE |
+		UNIPHIER_PINCTRL_CAPS_PERPIN_IECTRL,
 };
 
 static int uniphier_ld20_pinctrl_probe(struct udevice *dev)