Implement gm20b specific gr ops. Bug 1387211 Change-Id: I4523311f1c155ba2d3403dcf222769f6817b2450 Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com> Reviewed-on: http://git-master/r/362415 Reviewed-by: Kevin Huang (Eng-SW) <kevinh@nvidia.com>