drm/tegra: Annotate dma-fence critical section in commit path

Again ends just after drm_atomic_helper_commit_hw_done(), but with the
twist that we need to make sure we're only annotate the custom
version. And not the other clause which just calls
drm_atomic_helper_commit_tail_rpm(), which is already annotated.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: linux-tegra@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20210121152959.1725404-11-daniel.vetter@ffwll.ch