V4L/DVB (7346): tda9887: allow multiple driver instances for the same hardware to share state

Convert tda9887 to use the new hybrid_tuner_request_state and
hybrid_tuner_release_state macros to manage state sharing between
hybrid tuner instances.

Some ATSC/DVB cards need to put the analog demodulator into standby
before tuning digital.  This patch allows us to attach the tda9887
driver to the digital side of the bridge driver and be able to put
it into standby without jeopardizing the analog demod driver's state.

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>