linux-imx

[media] cxd2841er: provide signal strength for DVB-C

Currently, there's no stats for DVB-C. Let's at least return
signal strength. The scale is different than on DVB-T, so let's
use a relative scale, for now.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>