msm: kgsl: use GMU to manage GPU power

Add adaptation APIs to manage GPU power via GMU or legacy driver
depending on GMU availability.

CRs-Fixed: 2017390
Change-Id: I60d95314bead64d07abae980be92bd485f365047
Signed-off-by: Kyle Piefer <kpiefer@codeaurora.org>
Signed-off-by: George Shen <sqiao@codeaurora.org>