pinctrl: abx500: Fix header file include guard

Fix a trivial typo.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-abx500.h

-#ifndef PINCTRL_PINCTRL_ABx5O0_H
+#ifndef PINCTRL_PINCTRL_ABx500_H
 #define PINCTRL_PINCTRL_ABx500_H
 
 /* Package definitions */