Add implementation for an abstracted condition variable. Implement it using wait queue in Linux. JIRA NVGPU-14 Change-Id: I211c590cca940ffc31d6c52141689f23f231e7da Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com> Reviewed-on: http://git-master/r/1469763 Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com> Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>