Break tuner.ko into separate modules. This was a quick change -
Tuner sub-drivers are still static-linked to tuner.ko, this will
change after using dvb_attach and removing the probing functions.

After this change, one can deselect undesired tuner sub-drivers via Kconfig.
Signed-off-by: NMichael Krufky <mkrufky@linuxtv.org>
Acked-by: NHans Verkuil <hverkuil@xs4all.nl>
Acked-by: NMike Isely <isely@pobox.com>
Acked-by: NSteven Toth <stoth@hauppauge.com>
Acked-by: NPatrick Boettcher <pb@linuxtv.org>
Acked-by: NJarod Wilson <jwilson@redhat.com>
Acked-by: NTrent Piepho <xyzzy@speakeasy.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>