drm/mediatek: Rename files "mtk_drm_gem.h" to "mtk_gem.h"

Rename files mtk_drm_gem.h to mtk_gem.h.

Reviewed-by: AngeloGioacchino Del Regno <[e-mail]>
Reviewed-by: CK Hu <[e-mail]>
Signed-off-by: Hsiao Chien Sung <[e-mail]>
Link: https://patchwork.kernel.org/project/dri-devel/patch/[e-mail]/
Signed-off-by: Chun-Kuang Hu <[e-mail]>

drivers/gpu/drm/mediatek/mtk_crtc.c

···
 #include "mtk_crtc.h"
 #include "mtk_ddp_comp.h"
 #include "mtk_drm_drv.h"
-#include "mtk_drm_gem.h"
+#include "mtk_gem.h"
 #include "mtk_plane.h"
 
 /*

drivers/gpu/drm/mediatek/mtk_drm_drv.c

···
 #include "mtk_crtc.h"
 #include "mtk_ddp_comp.h"
 #include "mtk_drm_drv.h"
-#include "mtk_drm_gem.h"
+#include "mtk_gem.h"
 
 #define DRIVER_NAME "mediatek"
 #define DRIVER_DESC "Mediatek SoC DRM"

drivers/gpu/drm/mediatek/mtk_drm_gem.c

···
 #include <drm/drm_prime.h>
 
 #include "mtk_drm_drv.h"
-#include "mtk_drm_gem.h"
+#include "mtk_gem.h"
 
 static int mtk_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
 

drivers/gpu/drm/mediatek/mtk_plane.c

···
 #include "mtk_crtc.h"
 #include "mtk_ddp_comp.h"
 #include "mtk_drm_drv.h"
-#include "mtk_drm_gem.h"
+#include "mtk_gem.h"
 #include "mtk_plane.h"
 
 static const u64 modifiers[] = {