V4L/DVB (13376): cx-usb: add Mygica D689 DMB-TH USB support

X-Patchwork-Id: 55873

Add support for cxusb card Mygica D689 DBM-TH USB

Signed-off-by: David T. L. Wong <davidtlwong@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>