drm/exynos: staticize exynos_drm_gem_init()

The exynos_drm_gem_init() is used only in exynos_drm_gem.c file. Make it
static and don't export it.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index 85aeae9..5638a7a 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -187,8 +187,7 @@
 	return exynos_gem_obj->size;
 }
 
-
-struct exynos_drm_gem_obj *exynos_drm_gem_init(struct drm_device *dev,
+static struct exynos_drm_gem_obj *exynos_drm_gem_init(struct drm_device *dev,
 						      unsigned long size)
 {
 	struct exynos_drm_gem_obj *exynos_gem_obj;