msm: kgsl: Implement the A4XX power-on shader workaround

On A4xx targets the hardware is in a wonky state following
a power collapse. Send a special command buffer before the first
submission to put everything back in place.

Change-Id: I0730f1e850bc2f0a99ef0a68e8819e78b0781cc3
Signed-off-by: Anshuman Dani <adani@codeaurora.org>