gpu: nvgpu: Use HAL for waiting for GR quiet

gpu: nvgpu: Use HAL for waiting for GR quiet

Create a HAL for waiting for GR to become quiet. Use it forall cases
where we require GR to be quiet, but where it does not need to be
idle.

Bug 1640378

Change-Id: Ic0222d595a2d049e0fa8864b069ab94a97fac143
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/745639
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: Seshendra Gadagottu <sgadagottu@nvidia.com>