bsc: TC_chan_exhaustion: Send correct RA to alloc all different channels

Previous RA value (23, Establishment cause = 0010XXXX) meant MS was dual
rate capable but was asking speciifically for only TCH/F channel. As a
result, TCH/H was not being allocated and an immediate assignment reject
was sent.

Change-Id: I3e58592c661fc004e648dbe46b67a3b3f5a20bc8
1 file changed