pinctrl: at91-pio4: fix non-exported functions

The atmel_pctl_find_group_by_pin() and the atmel_pinctrl_remove()
functions are not exported, so fix the warnings about these
being exported without definitions by making them static.

drivers/pinctrl/pinctrl-at91-pio4.c:424:20: warning: symbol 'atmel_pctl_find_group_by_pin' was not declared. Should it be static?
drivers/pinctrl/pinctrl-at91-pio4.c:1077:5: warning: symbol 'atmel_pinctrl_remove' was not declared. Should it be static?
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Acked-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-at91-pio4.c

@@ -421,8 +421,8 @@ static int atmel_pctl_get_group_pins(struct pinctrl_dev *pctldev,
 	return 0;
 }
 
-struct atmel_group *atmel_pctl_find_group_by_pin(struct pinctrl_dev *pctldev,
-						 unsigned pin)
+static struct atmel_group *
+atmel_pctl_find_group_by_pin(struct pinctrl_dev *pctldev, unsigned pin)
 {
 	struct atmel_pioctrl *atmel_pioctrl = pinctrl_dev_get_drvdata(pctldev);
 	int i;
@@ -1074,7 +1074,7 @@ static int atmel_pinctrl_probe(struct platform_device *pdev)
 	return ret;
 }
 
-int atmel_pinctrl_remove(struct platform_device *pdev)
+static int atmel_pinctrl_remove(struct platform_device *pdev)
 {
 	struct atmel_pioctrl *atmel_pioctrl = platform_get_drvdata(pdev);