V4L/DVB (6127): tuner: kill i2c_client interface to tuner sub-drivers

To ease the conversion of the analog tuner sub-drivers into dvb_frontend
style tuner modules, we must remove the i2c_client interface.

dvb_frontend style tuner modules use i2c_transfer directly on the i2c_adapter.

This change only alters the interface between tuner.ko and the tuner
sub-drivers. The v4l2 / i2c_client interface to tuner.ko remains intact.

This patch adds inline functions tuner_i2c_xfer_send, and tuner_i2c_xfer_recv,
to replace i2c_master_send and i2c_master_recv inside the tuner sub-drivers.

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: Mike Isely <isely@pobox.com>
Acked-by: Steven Toth <stoth@hauppauge.com>
Acked-by: Patrick Boettcher <pb@linuxtv.org>
Acked-by: Jarod Wilson <jwilson@redhat.com>
Acked-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>