manifest: Remove mtk-specific poky repository
It is not possible to use a single commit for both platforms, but at least we can rebase MTK's poky commits into the same branch that used for NXP. Then https://git.seco.com/seco-ne/3rd-party/yocto/poky_mtk can be removed.
Change-Id: Icf92b1cbf74e2ba0c14b69c90ecfd46d5a5c2f72
Edited by Oleksii Kutuzov