Commit
              4b081b1d8862114f59af433b943dea86ce47ac71
              by pmaier@sysmocom.degsm0808: fix wrong codec defaults for OFR_AMR_WB
3GPP TS 48.008 chapter 3.2.2.103 states that the configuration bits of 
OFR_AMR_WB are coded as follows:
"S0, S2, S4 indicates the supported Codec Configurations. S1, S3, S5,
S6, S7 are reserved and coded with zeroes."
The current default setting of 0x3F violates this requirement. Lets set 
the "forbidden" settings zu zero and keep only the allowed ones.
Change-Id: I4a481def59e9c98cfdcafc2b80c0ac7df0c14130