DSME: Track "charger" connection with the usbtracker module

Based on the connection state we decide if a charger is connected or not.
When a USB cable is connected we should be charging (except for error conditions).

Fixes: JB#6580

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
'Fix' indentation

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
usbtracker: * track dedicated charger, not only cable
            * only send signals when the connection status changes

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
Fix typo in variable name
Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
logic fixes

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
Add usb_moded query on start-up to know charger state

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>
Do not block while making usb_moded mode_request over D-Bus

DSME should not block while waiting for usb_moded to reply, using
pending call takes care of that.

Also uses mode != "undefined" as charger connected instead of
mode == "dedicated_charger".

[dsme] Do not block while making usb_moded mode_request over D-Bus

Signed-off-by: Simo Piiroinen <simo.piiroinen@jollamobile.com>
Merge pull request #1 from spiiroin/async_usb_mode_query

usb mode query