gpu control: reworked and introduced over-/underlock

This patch fixes some bugs of the previous version
and saves some cpu circles.
Its now possible to completely active or deactive the
new control driver.

Although the main scheduling algorithm isn't implemented
yet, it works quite well. Users have now the opportunity
to overclock or underclock their gpu if desired.

For now its locked to 250,0mhz which is already a 25%
increase.

All parameters are located unter /sys/kernel/gpu_control

Change-Id: Ibe6354b97bfd469e01facfb7eca2417cdd5af73d
Signed-off-by: Blechd0se <alex.christ@hotmail.de>
gpu control: enable it in defconfig

For now i will only enable it for Defy on 4.2
because i haven't tested other devices on other
versions of android.

Change-Id: I889cee915421e04403c0877943b0b09c91fee51d
Signed-off-by: Blechd0se <alex.christ@hotmail.de>