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-pxs2.c b/drivers/pinctrl/uniphier/pinctrl-uniphier-pxs2.c
index 1d29170..60777c3 100644
--- a/drivers/pinctrl/uniphier/pinctrl-uniphier-pxs2.c
+++ b/drivers/pinctrl/uniphier/pinctrl-uniphier-pxs2.c
@@ -140,6 +140,7 @@
 	.groups_count = ARRAY_SIZE(uniphier_pxs2_groups),
 	.functions = uniphier_pxs2_functions,
 	.functions_count = ARRAY_SIZE(uniphier_pxs2_functions),
+	.caps = UNIPHIER_PINCTRL_CAPS_PUPD_SIMPLE,
 };
 
 static int uniphier_pxs2_pinctrl_probe(struct udevice *dev)