[media] rtl2832_sdr: expose e4000 controls to user

E4000 tuner driver provides now some controls. Expose those to
userland.

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

diff --cc drivers/staging/media/rtl2832u_sdr/rtl2832_sdr.c
Simple merge