video: tegra: host: map command buffer if tracing is enabled

video: tegra: host: map command buffer if tracing is enabled

Map the command buffer only if tracing is enabled.
Buffer mapping is required only for command tracing
otherwise there is no need to map.

Change-Id: If433e1dec78322f415b2f5370d1a6e7b2346c4e9
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/427020
(cherry picked from commit e42b2925ca54e8a27a833d1008318a095a18f1e6)
Reviewed-on: http://git-master/r/427655
GVS: Gerrit_Virtual_Submit
Reviewed-by: Sachin Nikam <snikam@nvidia.com>