bts: Test AMR in TC_speech_rtp_tch{h,f}()

Related: SYS#5987
Requires: osmocom-bb.git Ib80be434c06d07b3611bd18ae25dff8b14a7aad9 (trxcon)
Change-Id: I8cf7792a00b0a858f6a02bf5cb0d283484b820eb
2 files changed