Import dhcpcd-6.6.1 with the following changes:
  *  Improve handling of the IPv6LL address at startup
  *  Support old Linux kernels where IFLA_AF_SPEC may not exist
  *  When stopping interfaces, skip past pseudo interfaces instead
     of finding the master as only the masters are sorted correctly

RCSIDs have been removed from the import and will be added afterwards
as patches as technically they are not part of the dhcpcd project directly.
Hopefully this will be future imports less painful.
Reimport dhcpcd-6.6.1 with correct hooks