pinctrl: at91: initialize config parameter to 0

When passing a not initialized config parameter, at91_pinconf_get() would return
a bogus value. Fix that by initializing it to zero before using it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/pinctrl-at91.c b/drivers/pinctrl/pinctrl-at91.c
index 6446dc8..b0b78f3 100644
--- a/drivers/pinctrl/pinctrl-at91.c
+++ b/drivers/pinctrl/pinctrl-at91.c
@@ -722,7 +722,8 @@
 	unsigned pin;
 	int div;
 
-	dev_dbg(info->dev, "%s:%d, pin_id=%d, config=0x%lx", __func__, __LINE__, pin_id, *config);
+	*config = 0;
+	dev_dbg(info->dev, "%s:%d, pin_id=%d", __func__, __LINE__, pin_id);
 	pio = pin_to_controller(info, pin_to_bank(pin_id));
 	pin = pin_id % MAX_NB_GPIO_PER_BANK;