media: Kconfig: not all V4L2 platform drivers are for camera

When the platform drivers got added, they were all part of
complex camera support. This is not the case anymore, as we
now have codecs and other stuff there too.

So, fix the dependencies, in order to not require users to
manually select something that it doesn't make sense.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>