This patch adds .is_railgated() callback for the generic gpu platform. Change-Id: Ief13a6fba82b376aafbe861e8f3823a19bb7f679 Signed-off-by: Arto Merilainen <amerilainen@nvidia.com> Reviewed-on: http://git-master/r/433059 Reviewed-by: Hiroshi Doyu <hdoyu@nvidia.com> Reviewed-by: Automatic_Commit_Validation_User