gpiolib: Use spinlock_t instead of struct spinlock

For spinlocks the type spinlock_t should be used instead of "struct
spinlock".

Use spinlock_t for spinlock's definition.

Cc: linux-gpio@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20190704153803.12739-8-bigeasy@linutronix.deReviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib.h

@@ -210,7 +210,7 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep,
 				  struct gpio_array *array_info,
 				  unsigned long *value_bitmap);
 
-extern struct spinlock gpio_lock;
+extern spinlock_t gpio_lock;
 extern struct list_head gpio_devices;
 
 struct gpio_desc {