[media] lmedm04: create frontend callbacks for signal/snr/ber/ucblocks

Create call backs dm04_read_signal_strength, dm04_read_snr and
move dm04_read_ber and dm04_read_ucblocks for all frontends

Removing the I2C filtering from lme2510_msg and the old rs2000 callbacks.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>