V4L/DVB (13091): cx23885: Enable HVR-1850 CX23888 A/V core to get VID_CLK running for IR

For the IR controller on the CX23888 to work for the HVR-1850 and in
general, the A/V core must be initialized to get the VID_CLK going.
The VID_CLK is the timing reference for the CX23888's integrated
IR controller.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>