gpiolib: remove duplicate inclusions

Remove second `#include <linux/err.h>`. Remove `#include <asm/errno.h>`
too as it's included by `err.h`.

Signed-off-by: Wang Jinchao <[e-mail]>
Signed-off-by: Bartosz Golaszewski <[e-mail]>

include/linux/gpio/driver.h

···
 #else
 
 #include <asm/bug.h>
-#include <asm/errno.h>
 
 static inline int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
 					      struct irq_domain *domain)
···
 const char *gpio_device_get_label(struct gpio_device *gdev);
 
 #else /* CONFIG_GPIOLIB */
-
-#include <linux/err.h>
 
 #include <asm/bug.h>