bts-trx: Don't set OPSTATE enabled during trx_init
bts-trx: Don't set OPSTATE enabled during trx_init

At that time we schedule a POWERON command towards osmo-trx, so let the
callback of RSP POWERON set the OPSTATE in l1if_poweronoff_cb rather
than setting it without waiting for confirmation from osmo-trx.

Change-Id: Ib36a073cae5e1522821a04d8806648562f4e0f5b

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