[msm] Enable battery charging flag based on power-on status

Determine power-on reason (e.g. due to USB cable connection,
button press, etc.) and pass androidboot.battchg_pause to kernel.

Enable flag on msm7627_* targets when power-on due to USB
cable connection.  This will trigger a pause during bootup
until user keypad input.

Change-Id: I7751d9d7bdd0e735cd5cdeeedb952879cb237005
5 files changed