When transitioning between power-low and power-on modes, Telit modems
switch the SIM off/on, which leads to the emission of #QSS unsolicited not
related to actual SIM swaps.
To handle this #QSS unsolicited, this patch:
* disables reacting on #QSS unsolicited when modem_power_down is received
* implements modem_after_power_up that:
- checks whether the SIM has been changed, matching cached SIM
Identifier with the value in the current SIM. If SIM Identifier,
is different, sim hot swap ports detected is called.
- re-enables reacting on #QSS unsolicited