msm: kgsl: Refactor getproperty/setproperty

To support upcoming capabilities changes, first rework the getproperty
and setproperty for both KGSL and adreno to make it less complex and
easier to fit in with the upcoming model.

Change-Id: Ic0dedbad023d23ddb74f9d0208111e168554f0b6
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>