gpu: nvgpu: do not idle timed out channels

gpu: nvgpu: do not idle timed out channels

While suspending the device, do not submit WFI on
timed out channels

Submitting WFI on timed out channels will cuase submit_wfi()
to return error and as result of this, rail gating of device
will be prevented

Bug 200010416

Change-Id: Ic097bfdae59dbf9e1f2aea5d8d0431b5f1c3721b
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/422743
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>