add usb fastcharge.

Change-Id: I52f189f375eaffbfe610b57f945ead9d79900f6f

Conflicts:
	include/linux/fastchg.h
Turn fast charge off by default

Turn on:
echo 1 > /sys/kernel/fast_charge/force_fast_charge

Turn off:
echo 0 > /sys/kernel/fast_charge/force_fast_charge

Credits, franciscofranco, Paul Reioux

Change-Id: I4c1b14a6f47c10e2148338bce33534ba47108f79

Conflicts:
	drivers/usb/otg/msm_otg.c