HACK: add sysfs interface to ziddey's MSM OTG hack for N4

this allows for normal / OTG Hack based on user sysfs command.
minor code clean up as well.

Signed-off-by: Paul Reioux <reioux@gmail.com>

Conflicts:

	drivers/usb/otg/msm_otg.c
Revert "HACK: add sysfs interface to ziddey's MSM OTG hack for N4"

This reverts commit 0b4279a6c1bb1355971f1db707ab9250b09e3304.