media: mtk-mdp: Remove mtk_mdp_comp.id and supporting functionality

Since components are registered in a list, the numeric component id that
specified a location in an array is not necessary.

Signed-off-by: Eizan Miyamoto <eizan@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>