drm/mediatek: Fix uninitialized symbol

Fix Smatch static checker warning
  -Fix uninitialized symbol comp_pdev in mtk_ddp_comp_init.

Fixes: 0d9eee91 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195")
Signed-off-by: Nancy.Lin <nancy.lin@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20230803094843.4439-1-nancy.lin@mediatek.com/


Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>