[media] lmedm04: add read snr, signal strength and ber call backs

This allows calling the original functions providing the streaming is off.

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

diff --cc drivers/media/usb/dvb-usb-v2/lmedm04.c
Simple merge