Revert "Voltage Control: add sysfs interface"

This reverts commit ff36b983b8524b4b389eb9708aaf8743cd269455.
Voltage Control: initial voltage control for MSM S4-Pro SOC

Signed-off-by: Paul Reioux <reioux@gmail.com>
Voltage Control: add sysfs interface

Signed-off-by: faux123 <reioux@gmail.com>