V4L/DVB (6834): cx88-video: Enable selection of the WM8775 for cx88 cards
The auto selection of pertinent helper chips (VIDEO_HELPER_CHIPS_AUTO)
should select the wm8775 driver, which is used by at least one
Conexant 2388x based card (Hauppauge HVR-1300), if VIDEO_CX88 is
selected.