The setup in Cinterion modems goes as follows:
AT+CNMI=<mode>[, <mt>[, <bm>[, <ds>[, <bfr>]]]]
For each field, several setups are available, so we could use a default value,
as we were doing until now (+CNMI=2,1,2,2,1).
BUT, not every Cinterion modem allows the same set of settings. For example, the
new PHS8 only allows '0' for the <ds> value:
AT+CNMI=?
+CNMI: (0,1,2),(0,1),(0,2),(0),(1)
So, instead of hardcoding the setup, try to find the best suitable one for each
modem. We'll parse the +CNMI=? test response to know which values are supported
during the messaging support check, which is run once during initialization.