osmo-bts-trx: print timeslot brief info in 'show transceiver'
osmo-bts-trx: print timeslot brief info in 'show transceiver'

Change-Id: Ibe624e4b801cae2dc00feb99441b7d606005b846

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