video: tegra: nvmap: Move pool lock functions

video: tegra: nvmap: Move pool lock functions

Move the pool lock/unlock functions to the nvmap private
header file.

Bug 1371433
Bug 1392833
Bug 1561572

Change-Id: Iea9e5aee852fc09b1db60b49db69c4471257b2fc
Reviewed-on: http://git-master/r/337531
Signed-off-by: Jon McCaffrey <jmccaffrey@nvidia.com>
Reviewed-on: http://git-master/r/601340
(cherry picked from commit 03a39add2cc7c4b679e63b2e5087fb5a6a68edf1)
Reviewed-on: http://git-master/r/601414
Reviewed-by: Todd Poynter <tpoynter@nvidia.com>
Tested-by: Todd Poynter <tpoynter@nvidia.com>