video: tegra: nvmap: Add pin, unpin trace events

Change-Id: I62deda9d607476e3dc82428b872ad1a3e396e37e
Signed-off-by: Krishna Reddy <vdumpa@nvidia.com>
Reviewed-on: http://git-master/r/143421
Reviewed-by: Mrutyunjay Sawant <msawant@nvidia.com>
Tested-by: Mrutyunjay Sawant <msawant@nvidia.com>