[media] cx23885: add support for HVR-1255 analog (cx23888 variant)

Get the HVR-1255 analog support working for all supported inputs.  This
includes introduction of a new board profile for an OEM variant which
doesn't have all the same inputs as the retail version of the board.

Validated with the following boards:

HVR-1255 (0070:2259)

Thanks to Steven Toth and Hauppauge for	loaning	me various boards to
regression test	with.

Thanks-to: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Devin Heitmueler <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>