gpio: zynq: use module_platform_driver to simplify the code

module_platform_driver() makes the code simpler by eliminating
boilerplate code.
Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/gpio-zynq.c

@@ -1020,22 +1020,7 @@ static struct platform_driver zynq_gpio_driver = {
 	.remove = zynq_gpio_remove,
 };
 
-/**
- * zynq_gpio_init - Initial driver registration call
- *
- * Return: value from platform_driver_register
- */
-static int __init zynq_gpio_init(void)
-{
-	return platform_driver_register(&zynq_gpio_driver);
-}
-postcore_initcall(zynq_gpio_init);
-
-static void __exit zynq_gpio_exit(void)
-{
-	platform_driver_unregister(&zynq_gpio_driver);
-}
-module_exit(zynq_gpio_exit);
+module_platform_driver(zynq_gpio_driver);
 
 MODULE_AUTHOR("Xilinx Inc.");
 MODULE_DESCRIPTION("Zynq GPIO driver");