[media] cx23885: Hauppauge HVR1850 Analog driver support

First in a series of patches that adds support to the cx23885 driver
for CX23888 analog video handling. Raw and MPEG video support is
being added for the HVR1850 driver in the patch, and the following
series of patches.

Some basic cx23885 driver cleanup. Partly to add HVR1850 support
and partly to allow -417.c V4L2 calls to be routed through thr
driver core and handled in a single place.

Make a number of core driver functions available to the -417.c
driver to streamline the driver.

Add the analog tuner ops definition so we can reach/tune the
hardware when we need to. Added the tff field so 888 based cards
(which have a weird field ordering issue) can be accomodated
and worked around in the driver.

Signed-off-by: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>