sysmobts: make L1 power configurable
sysmobts: make L1 power configurable

The TRX nominal output power (as seen by OML) is the aggregate power
of any gain internal to the sysmoBTS (and managed by L1) and any
external PA.  This is what is used in trx->nominal_power;

fl1h->l1_power is the transmit power to which we configure the sysmoBTS
L1.  This is 23 dBm (200mW) by default in the sysmoBTS 1002, and 40 dBm
(5W) in the sysmoBTS 2050.  However, if sysmoBTS 2050 is used in
single-TRX configuration, it may be used with higher power, which we can
now configure in the config file / vty.

TODO: A separate, additional field that keeps track of any gain added by
an external PA, e.g. if the sysmoBTS 1002 is used with a sysmoAMP.

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