[media] radio-gemtek-pci: remove duplicate driver

The radio-gemtek-pci driver is for the same hardware as the radio-maxiradio
driver which uses the same GemTek PR103 and tea5757 combination and the two
drivers are identical. I chose the maxiradio over the gemtek-pci driver since
the maxiradio has support for mono/stereo detection.

Tested with my gemtek-pci card.

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