drm/msm: Remove unnecessary pm_runtime_get/put

We already enable gpu power from msm_gpu_submit(), so avoid a duplicate
pm_runtime_get/put from msm_job_run().

Signed-off-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/498390/
Link: https://lore.kernel.org/r/20220819015030.v5.1.Icf1e8f0c9b3e7e9933c3b48c70477d0582f3243f@changeid
Signed-off-by: Rob Clark <robdclark@chromium.org>