sh: improve pinmux support for single direction pins

This patch improves the support for gpio pins that are hard wired
to either input or output and lack control register association.
A special force enum id is used to allow use without control
register but still mark the gpio pin as input or output.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/gpio.c

@@ -267,9 +267,13 @@ int pinmux_config_gpio(struct pinmux_info *gpioc, unsigned gpio,
 			break;
 
 		in_range = enum_in_range(enum_id, &gpioc->function);
-		if (!in_range && range)
+		if (!in_range && range) {
 			in_range = enum_in_range(enum_id, range);
 
+			if (in_range && enum_id == range->force)
+				continue;
+		}
+
 		if (!in_range)
 			continue;