Extract out the part to construct a runlist entry for a tsg and its channels. The higher-level logic of ordering the runlist entries is about to change. Jira NVGPU-1174 Change-Id: I7c0dd30a7313d1feb29945a6e4ca17f764e78877 Signed-off-by: Konsta Holtta <kholtta@nvidia.com> Reviewed-on: https://git-master.nvidia.com/r/1918225 Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com> Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>