V4L/DVB (6243): [PATCH 2/2] GemTek Radio card

Details now match with radio-gemtek.c, eg. no more different ports.
Included a short note about cards that should be compatible with
radio-gemtek module.

Signed-off-by: Pekka Seppanen <pexu@kapsi.fi>
Signed-off-by: Douglas Schilling Landgraf <dougsland@gmail.com>
Reviewed-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>