[media] cx25840: fix regression in analog support hue/saturation controls

Fix regression in HVR-1800 analog support hue/saturation controls.

The changes made for the cx23888 caused regressions in the analog
support for cx23885/cx23887 based boards (partly due to changes in the
locations of the hue/saturation controls).  As a result the wrong
registers were being overwritten.

Add code to use the correct registers if it's a cx23888

Validated with the following boards:

HVR-1800 retail (0070:7801)
HVR-1800 OEM (0070:7809)
HVR-1850 retail (0070:8541)

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

Reported-by: Jonathan <sitten74490@mypacks.net>
Thanks-to: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Devin Heitmueler <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>