[media] DRX-K: Initial check-in

Driver for the DRX-K DVB-C/T demodulator.

Signed-off-by: Ralph Metzler <rjkm@metzlerbros.de>
Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>