HACK: register the GPIO driver earlier to ensure that gpio_request calls
from mach files succeed.

Index: linux-4.14.18/drivers/gpio/gpio-ath79.c
===================================================================
--- linux-4.14.18.orig/drivers/gpio/gpio-ath79.c
+++ linux-4.14.18/drivers/gpio/gpio-ath79.c
@@ -322,7 +322,11 @@ static struct platform_driver ath79_gpio
 	.remove = ath79_gpio_remove,
 };
 
-module_platform_driver(ath79_gpio_driver);
+static int __init ath79_gpio_init(void)
+{
+	return platform_driver_register(&ath79_gpio_driver);
+}
+postcore_initcall(ath79_gpio_init);
 
 MODULE_DESCRIPTION("Atheros AR71XX/AR724X/AR913X GPIO API support");
 MODULE_LICENSE("GPL v2");