pinctrl: get_group_pins() const fixes

get_group_pins() "returns" a pointer to an array of const objects, through
a pointer parameter. Fix the prototype so what's pointed at by the returned
pointer is const, rather than the function parameter being const.

This also allows the removal of a cast in each of the two current pinmux
drivers.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/pinmux-sirf.c b/drivers/pinctrl/pinmux-sirf.c
index c48c563..ddcea18 100644
--- a/drivers/pinctrl/pinmux-sirf.c
+++ b/drivers/pinctrl/pinmux-sirf.c
@@ -869,12 +869,12 @@
 }
 
 static int sirfsoc_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
-			       unsigned ** const pins,
-			       unsigned * const num_pins)
+			       const unsigned **pins,
+			       const unsigned *num_pins)
 {
 	if (selector >= ARRAY_SIZE(sirfsoc_pin_groups))
 		return -EINVAL;
-	*pins = (unsigned *) sirfsoc_pin_groups[selector].pins;
+	*pins = sirfsoc_pin_groups[selector].pins;
 	*num_pins = sirfsoc_pin_groups[selector].num_pins;
 	return 0;
 }