codec_pref: also check physical channels

At the moment codec_pref only checks the codec configuration, but it
does not check if there is actually a matching physical channel
available. This should be checked too we must make sure that the codec
we select fits the physical channels available on the BTS.

Change-Id: I2d29dfed450e5ef93c26ed5ec9fdc0730eb3d7dd
Related: OS#3503
2 files changed