V4L/DVB (9215): si470x: improvement of unsupported base controls

This patch changes the handling of unsupported base controls.

In the former version, specific unsupported base controls were listed in
the queryctrl table and were flagged as disabled controls. This was done
for all base controls used by the applications.

The patch now removes the specific base controls and instead lets
queryctrl automatically return unsupported base controls flagged as
disabled.

Signed-off-by: Tobias Lorenz <tobias.lorenz@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>