onboard xfs upstream tree

Onboard the xfs trees:

• https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git/?h=for-next
  • kernel from https://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git/?h=for-next
• https://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git/?h=for-next
  • xfsprogs from https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git/?h=for-next

arches:

• all 4 arches

test:

• xfstests - xfs (needs to pass XFSPROGS_GITREPO and XFSPROGS_GITBRANCH as test env parameters)

Requested by @cmaiolino