drm/exynos/decon5433: Remove the unused include statements

This driver doesn't reference of_gpio.h, so drop it.
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos5433_drm_decon.c

@@ -13,7 +13,6 @@
 #include <linux/irq.h>
 #include <linux/mfd/syscon.h>
 #include <linux/of_device.h>
-#include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>