V4L/DVB (5607): M920x: Initial support for devices likely manufactured by Dposh

These devices are sold by various companies and chains not involved in
hardware manufacturing business. This particular device owned by
winisch (from irc) had a sticker with text "TCM 234292" on it. This device
was never opened so it is possible that Dposh did not manufacture this
stick. However, the bundled software and their product line points into
that direction. Also thanks to Michael Krufky for spotting this hw
filtering problem and thus avoiding hair loss.
Hardware pid filters and the bundled remote controller are not currently
supported on this device.

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>