manifest: grouping of device,vendor & kernel trees

Change-Id: I62e2869addf782daa93edd746b1352c50b8346b8
Signed-off-by: Arnav Gupta <championswimmer@aokp.co>
Merge branch 'jb-mr2' of https://github.com/KhasMek/platform_manifest into jb-mr2

Conflicts:
	default.xml

Change-Id: If28946c02c8f9b0708f7d08749df87b89170b78a