As CEC support doesn't depend on MEDIA_SUPPORT, let's
place the platform drivers outside the media menu.

As a side effect, instead of depends on PCI, seco driver
can select it (and DMI).
Acked-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>