[media] shark2: New driver for the Griffin radioSHARK v2 USB radio receiver

This driver consists of 2 parts, a generic tea5777 driver and a driver
for the Griffin radioSHARK v2 USB radio receiver, which is the only driver
using the generic tea5777 for now.

This first version only implements FM support, once the the new
VIDIOC_ENUM_FREQ_BANDS API is upstream I'll also add AM support.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>