[media] mn88472: implement DVB-T and DVB-T2

Implement initial support for DVB-T and DVB-T2 modes. Now driver has
basic support for all the modes, DVB-C/T/T2.

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