cosmetic: review mo_mt_sms.py's logging

Implement the Modem.log_info() function, use that instead of logging all modem
properties.

Tweak mo_mt_sms.py print() statements.

Pass modem object to SMS generation to inlcude the modem name as SMS token.

Change-Id: I2b17fce0b3b05594fd9038b54e5b65f5127bd0a4
diff --git a/suites/aoip_sms/mo_mt_sms.py b/suites/aoip_sms/mo_mt_sms.py
index 96e1caf..b9383ea 100755
--- a/suites/aoip_sms/mo_mt_sms.py
+++ b/suites/aoip_sms/mo_mt_sms.py
@@ -23,7 +23,12 @@
 
 ms_mo.connect(bsc)
 ms_mt.connect(bsc)
+
+ms_mo.log_info()
+ms_mt.log_info()
+
+print('waiting for modems to attach...')
 wait(msc.subscriber_attached, ms_mo, ms_mt)
 
-sms = ms_mo.sms_send(ms_mt.msisdn)
+sms = ms_mo.sms_send(ms_mt)
 wait(ms_mt.sms_was_received, sms)