Changes

csd_bs: fix setting of Rate Adaptation for FAX and 3.1 kHz audio

Some FAX machines, like Siemens based Possia Greta, refuse MT data
calls when the Rate Adaptation field is set to GSM48_BCAP_RA_V110_X30.
Using GSM48_BCAP_RA_NONE makes the Greta machine happy.

After looking at various tables in 3GPP TS 22.002, I deduced that
GSM48_BCAP_RA_V110_X30 shall only be used for Unrestricted Digital
Information.  Use GSM48_BCAP_RA_NONE for both FAX and 3.1 kHz audio.

Change-Id: I3d608f412859df8988ce7a51aaef65949c80865b
Related: OS#4394, OS#5730