V4L/DVB (5142): M920x: move filter caps from device caps to adapter caps

Move filter caps from device caps to adapter caps for the megasky driver.
This fixes usb1.1 operation.

Signed-off-by: Aapo Tahkola <aet@rasterburn.org>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>