bts-trx: Disable power-ramp

Power ramping features were implemented recently for osmo-bts-trx. We
don't want to enable them because it makes phones take longer (if even
at all) to find the network.

Change-Id: I35e2f560b28eddef886ad3b2f8ffb4ff79be77da

src/osmo_gsm_tester/templates/osmo-bts-trx.cfg.tmpl

@@ -52,4 +52,7 @@ bts 0
 %for chan in osmo_bts_trx.osmo_trx.channels:
  trx ${loop.index}
   phy 0 instance ${loop.index}
+  power-ramp max-initial 23000 mdBm
+  power-ramp step-size 2000 mdB
+  power-ramp step-interval 1
 %endfor