Add makefile support for T268 specific DT repos Bug 5235249 Change-Id: I4a0a049f850445f4afd7e39662853b19cff2f27b Signed-off-by: Vishwaroop A <va@nvidia.com> Reviewed-on: https://git-master.nvidia.com/r/c/linux/kernel-devicetree/+/3355735 Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com> GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com>