This patch introduces auto discovery of ST-Ericsson modems.
ST-Ericsson modems (M57XX, M7XX, M74XX) are managed by a
Modem Init Daemon responsible for start, power cycles,
flashing etc. This STE plugin monitors the modem state exposed
from the Modem Init Daemon's Dbus API. When the modem is in state
"on" the STE modem is created and registered. Muliple modem
instances, and reset handling is supported.