media: Kconfig: use a sub-menu to select supported devices

The media subsystem has hundreds of driver-specific options.
The *_SUPPORT config options work as a sort of filter,
allowing to reduce its complexity for users that won't
want to dig into thousands of options they don't need.

Yet, it the filtering options are becoming large. So, let's
place it on a sub-menu.

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