gpio: Remove duplicate include of errno.h

Currently, code include errno.h twice. Remove one inclusion
of errno.h

Signed-off-by: Vishwanathrao Badarkhe, Manish <manishv.b@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

include/linux/gpio.h

@@ -90,7 +90,6 @@ void devm_gpio_free(struct device *dev, unsigned int gpio);
 
 #include <linux/kernel.h>
 #include <linux/types.h>
-#include <linux/errno.h>
 #include <linux/bug.h>
 #include <linux/pinctrl/pinctrl.h>