Put the WWAN modem into low power mode during suspend

The WWAN modem has a low power mode that can wake the system during suspend. Enable this mode for power savings.

use-cases#75

changed the description

mentioned in issue #72 (closed)

Important thing regarding a possible non-connected suspend is to make sure the modem is turned off before suspending, as otherwise it's going to silently lose calls, appearing to the other call party as still connected even though there's no CPU to actually notice that call in any way.

I assume this is for the broadmobi. Where is this mode documented or how is it turned on?

mentioned in issue #156 (closed)

mentioned in commit 11b5d041

mentioned in commit ad3f7986