kgsl_pwrscale: Rework policy sysfs implementation

In the current implementation, the pwrscale policy kobj is
created when the pwrscale driver initializes.  It is then added
to the kobj hierarchy when a governor adds sysfs files.

When a governor removes sysfs files, it frees the kobj.

Then, when a new governor starts up, it attempts to add an
uninitialized kobj.  This fails.

Instead, use a constant kobj for the policy directory,
and add governor-specific attributes under it.  If a
sysfs group is given a name, all attributes in the group
will appear in a subdirectory with that name (see cpufreq
governor tuning variables).  Use this approach for our
governor tuning.

TODO (possibly in a future patch) - Rework this so the
governor attributes can be groups attached directly to
the pwrscale kobj.

Change-Id: I7b8ae6d5e690ee107be037ccaf2e737e52062feb
msm: kgsl: pwrscale functions should be run while GPU is ACTIVE

Base the decision to call power scaling functions on the current
state, not the requested state.  The GPU may not transition to the
requested state; call through based on current GPU state instead.

Change-Id: I1524bc92c908dc50a60b5815f2221ae3feef59be
CRs-Fixed: 441847
Signed-off-by: Lucille Sylvester <lsylvest@codeaurora.org>

Conflicts:
	drivers/gpu/msm/kgsl_pwrscale.c