[media] hackrf: HackRF SDR driver

V4L2 driver for HackRF SDR. Very basic version, with reduced
feature set. Driver implements receiver only, hardware supports
also transmitter.

USB ID 1d50:6089. Model HackRF One

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>