RLCMAC_EncDec: Provide decoded (m)cs in (E)GPRS data blocks

Let's provide this information to higher layer since CS is mostly
discovered by original bitstring size which is available during
decoding.

Call the size2mcs converter in each function to avoid having to pass it
as a parameter and have it selfcontained, meaning one can simply call
decode(bitstring) from TTCN3 code and be done with it.

Change-Id: I80ed44e575cc0a11510832e5bbfc07173e7b75b8
3 files changed