V4L/DVB (7932): cx18: mark Compro H900 as fully supported.

I always assumed that the Compro H900 could do digital as well,
but it turned out that it is an analog-only card.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>