V4L/DVB (5628): Add support for A-LINK DTU dvb-t adapter

Support for A-LINK DTU(m) is not included in this patch.

Signed-off-by: Aapo Tahkola <aet@rasterburn.org>
Acked-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>