pinctrl: uniphier: introduce capability flag

The core part of the UniPhier pinctrl driver needs to support a new
capability for upcoming UniPhier ARMv8 SoCs.  This sometimes happens
because pinctrl drivers include really SoC-specific stuff.

This commit intends to tidy up SoC-specific parameters of the existing
drivers before adding new ones.  Having flags would be better than
adding new members every time a new SoC-specific capability comes up.

At this time, there is one flag, UNIPHIER_PINCTRL_CAPS_DBGMUX_SEPARATE.
This capability (I'd say rather quirk) was added for PH1-Pro4 and
PH1-Pro5 as requirement from our customer.  For those SoCs, one pin-mux
setting is controlled by the combination of two separate registers; the
LSB bits at register offset (8 * N) and the MSB bits at (8 * N + 4).
Because it is impossible to update two separate registers atomically,
the LOAD_PINCTRL register should be set in order to make the pin-mux
settings really effective.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/pinctrl/uniphier/pinctrl-uniphier-pro4.c b/drivers/pinctrl/uniphier/pinctrl-uniphier-pro4.c
index b3eaf13..60fbbaf 100644
--- a/drivers/pinctrl/uniphier/pinctrl-uniphier-pro4.c
+++ b/drivers/pinctrl/uniphier/pinctrl-uniphier-pro4.c
@@ -103,9 +103,7 @@
 	.groups_count = ARRAY_SIZE(ph1_pro4_groups),
 	.functions = ph1_pro4_functions,
 	.functions_count = ARRAY_SIZE(ph1_pro4_functions),
-	.mux_bits = 4,
-	.reg_stride = 8,
-	.load_pinctrl = true,
+	.caps = UNIPHIER_PINCTRL_CAPS_DBGMUX_SEPARATE,
 };
 
 static int ph1_pro4_pinctrl_probe(struct udevice *dev)