Changes

bts: use proper ActType in f_TC_data_rtp_loopback()

For the sake of correctness, use c_RSL_IE_ActType_ASS (assignment)
when activating TCH/[FH] channels in TC_data_rtp_*.  This is the
kind of ActType that would normally be used by the BSC.

Change-Id: Ide773c3fcfdab881756d5fe5b6c314b0c0335043

bts: TC_data_rtp_tchh*: fix timeslot number in comments

Change-Id: I771e616d52315a26679acb1be17cd4f36eaa52b2

bts: add TC_data_facch_*: test FACCH/[FH] on data channels

So far we have been testing the actual traffic on TCH/[FH] in data
mode (CSD), but not FACCH/[FH].  Add separate testcases for that.

Half-rate variants of the new testcases crash osmo-bts-trx, so
comment them out in the control section until the problem is fixed.

Change-Id: I2098ccd651fc2a81f62e70be64af386ab0ca6148
Related: OS#6618