gpu: nvgpu: Allow suppressing WFI on submit

gpu: nvgpu: Allow suppressing WFI on submit

Allow suppressing WFI when submitting work and requesting a fence
back.

Bug 1491545

Change-Id: Ic3d061bb4f116cf7ea68dbd6a1b2ace9f11d0ab5
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/390457
Reviewed-on: http://git-master/r/671029
GVS: Gerrit_Virtual_Submit
Reviewed-by: Sibashis Mohapatra <sibashism@nvidia.com>
Tested-by: Sibashis Mohapatra <sibashism@nvidia.com>
Reviewed-by: Yogesh Kini <ykini@nvidia.com>
Reviewed-by: Winnie Hsu <whsu@nvidia.com>