pinctrl: uniphier: support pin configuration for dedicated pins

PH1-LD4 and PH1-sLD8 SoCs have pins that support pin configuration
(pin biasing, drive strength control), but not pin-muxing.

Allow to fill the mux value table with -1 for those pins; pins with
mux value -1 will be skipped in the pin-mux set function.  The mux
value type should be changed from "unsigned" to "int" in order to
accommodate -1 as a special case.

[ Linux commit: 363c90e743b50a432a91a211dd8b078d9df446e9 ]

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/pinctrl/uniphier/pinctrl-uniphier.h b/drivers/pinctrl/uniphier/pinctrl-uniphier.h
index 200d743..ff0a368 100644
--- a/drivers/pinctrl/uniphier/pinctrl-uniphier.h
+++ b/drivers/pinctrl/uniphier/pinctrl-uniphier.h
@@ -46,7 +46,7 @@
 	const char *name;
 	const unsigned *pins;
 	unsigned num_pins;
-	const unsigned *muxvals;
+	const int *muxvals;
 };
 
 /**