hotplug: add option to switch calc method

The new calculation method for the hotplug driver
seems to be a bit strange sometimes. Since i want to
do some more research here, just make it switchable
to the old method.
This could also be a very useful option if one would
port this driver to another device without the
quick get function.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
PM / devfreq: Fix simple_ondemand crashing

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Blechd0se <alex.christ@hotmail.de>
PM: devfreq: Fix show available freqs

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Blechd0se <alex.christ@hotmail.de>
PM: devfreq: Add conservative governor

A GPU governor is not rocket science. This one gets the job done pretty
smoothly while complying with devfreq framework rules.
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
PM: devfreq: Add some conservativeness

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Blechd0se <alex.christ@hotmail.de>
PM: devfreq: Always reflect a change of polling interval

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Blechd0se <alex.christ@hotmail.de>
PM: devfreq: conservative: Return 0 if GPU just started

Bailing out early is perfectly fine, so do not trigger an error in
update_devfreq.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Blechd0se <alex.christ@hotmail.de>
PM: devfreq: Add sysfs nodes for devfreq governors

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Blechd0se <alex.christ@hotmail.de>
devfreq: fix merge derp.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Blechd0se <alex.christ@hotmail.de>
devfreq: set simple_ondemand as default

It's just simple and performs quite nice.

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