USB forced fast charge v3.1

Use sysfs interface to change behaviour :

 * /sys/kernel/fast_charge/force_fast_charge (rw)
 *
 *   0 - disabled (default)
 *   1 - substitute AC to USB charging always
 *   2 - substitute AC to USB charging only if no USB peripheral is detected

For informational purposes I've also added the following read-only sysfs files :

 * /sys/kernel/fast_charge/USB_peripheral_detected (ro)
 *
 * The detection state will be returned in clear text (Yes/No).

 * /sys/kernel/fast_charge/USB_porttype_detected (ro)
 *
 * The port type will be returned in clear text.

 * /sys/kernel/fast_charge/is_fast_charge_forced (ro)
 *
 * The current force state will be returned in clear text (Yes/No).
 *
 * (requested by hawkeyexp)

New :

 * /sys/kernel/fast_charge/current_charge_mode (ro)
 *
 * The current charge mode will be returned in clear text (Discharging/AC/USB).
 *
 * (requested by hawkeyexp)

Conflicts:
	arch/arm/mach-msm/fastchg.c
	arch/arm/mach-msm/htc_battery_8x60.c
	drivers/usb/otg/msm_otg.c
	include/linux/fastchg.h