mediatek: Add MT8188G definition

To support MT8188G video pipeline.

BUG=b:256980241
TEST=emerge-geralt minigbm

Change-Id: If128d828aaae425813db283ed5aee28dcf16e753
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/minigbm/+/3998336
Tested-by: Fei Shao <fshao@chromium.org>
Reviewed-by: Hsin-Yi Wang <hsinyi@chromium.org>
Commit-Queue: Fei Shao <fshao@chromium.org>
diff --git a/mediatek.c b/mediatek.c
index f737bfd..f161b7d 100644
--- a/mediatek.c
+++ b/mediatek.c
@@ -36,6 +36,7 @@
 // clang-format off
 #if defined(MTK_MT8183) || \
     defined(MTK_MT8186) || \
+    defined(MTK_MT8188G) || \
     defined(MTK_MT8192) || \
     defined(MTK_MT8195)
 // clang-format on