make HR channels work for voice, not only signalling
make HR channels work for voice, not only signalling

without this, we would set a FR_V1 codec on a TCH/H channel, which
the L1 is obviously not happy with.

osmocom/osmo-bts,telenoobie/osmo-bts,telenoobie/osmo-bts,shimaore/osmo-bts,shimaore/osmo-bts,telenoobie/osmo-bts,geosphere/osmo-bts,osmocom/osmo-bts,shimaore/osmo-bts,osmocom/osmo-bts,telenoobie/osmo-bts,shimaore/osmo-bts,geosphere/osmo-bts,geosphere/osmo-bts,geosphere/osmo-bts