Merge tag 'csky-for-linus-4.20-fixup-dtb' of https://github.com/c-sky/csky-linux

Pull csky dtb fixups from Guo Ren:
 "These fix the csky dtb Kbuild to follow the new Devicetree dtb build
  rules"

* tag 'csky-for-linus-4.20-fixup-dtb' of https://github.com/c-sky/csky-linux:
  csky: use common dtb build rules
  csky: remove builtin-dtb Kbuild