media: dvb-usb-gl861: support I2C read from tuner via demod

Support Friio devices to read from tuner via demod tc90522,
by enabling the config option.

Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>