bsc: Allow setting expected ms max power level with module param

It will allow changing ms max power in osmo-bsc.cfg as well as TTCN3
expactancies in BSC_Tests.cfg easily in docker-playground.git without
needing to recompile or change code in TTCN3.

Change-Id: Ib00c96902377582bc32778c5b947a6b4274041aa
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index e25bf7f..e7a4c13 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -130,6 +130,8 @@
 	   unconditionally once new version of osmo-bsc is released (current
 	   version: 1.4.1) */
 	boolean mp_enable_osmux_test := true;
+	/* Value set in osmo-bsc.cfg "ms max power" */
+	uint8_t mp_exp_ms_power_level := 7;
 }
 
 private function f_gen_test_hdlr_pars() return TestHdlrParams {
@@ -140,6 +142,7 @@
 	} else {
 		pars.aoip := false;
 	}
+	pars.exp_ms_power_level := mp_exp_ms_power_level;
 
 	return pars;
 }