drm/mediatek: ovl_adaptor: Drop unused mtk_crtc.h header

None of the elements from that header is used in this file.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20240624-mtk_disp_ovl_adaptor_scoped-v1-1-9fa1e074d881@gmail.com/


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