dyn PDCH: lc15: chan_nr_by_sapi(): handle TCH/F_PDCH according to ts->flags
dyn PDCH: lc15: chan_nr_by_sapi(): handle TCH/F_PDCH according to ts->flags

Analogous to 0d10f0e482cdd50acc916e75a8b3ba1beb94227c on osmo-bts-sysmo.

According to the PDCH Active flag, handle a TS as TCH/F or PDCH.

Change-Id: I0c97b360136f76bdae8d70d06af9a31fdf75c1ba

osmocom/osmo-bts,osmocom/osmo-bts,osmocom/osmo-bts