Add lock_down_sm and wait_for_sm_lock_down gr ops
Required to support multiple SM and t19x SM register
address changes
JIRA GPUT19X-75
Change-Id: I529babde51d9b2143fe3740a4f67c582b7eb404b
Signed-off-by: Seema Khowala <seemaj@nvidia.com>
Reviewed-on: https://git-master/r/1514042
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>