drm/mediatek: separate color module to fixup error memory reallocation

Previous patch (c5f228ef drm/mediatek: add *driver_data for different
hardware settings) calls devm_kfree() and then devm_kzalloc() to
reallocate color module data structure.  But this reallocation cannnot
guarantee the new address is unchanged, but the caller will use the
old address, which is wrong.

Fix it by separate color module from general components, this patch
separate color module to independent files, like mtk_disp_ovl.c and
mtk_disp_rdma.c do

Fixes: c5f228ef ("drm/mediatek: add *driver_data for different hardware settings")
Signed-off-by: YT Shen <yt.shen@mediatek.com>
Tested-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
Signed-off-by: CK Hu <ck.hu@mediatek>