Merge tag 'kbuild-fixes-v5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git...

Pull more Kbuild fixes from Masahiro Yamada:

 - fix kselftest-merge to find config fragments in deeper directories

 - fix kconfig unit test, which was broken by SPDX tag addition

 - add + prefix to buildtar to suppress jobserver unavailable warning

 - fix checkstack.pl to recognize arch=arm64

 - suppress noisy warning from cc-cross-prefix

* tag 'kbuild-fixes-v5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: use more portable 'command -v' for cc-cross-prefix
  scripts/checkstack.pl: Fix arm64 wrong or unknown architecture
  kbuild: tar-pkg: enable communication with jobserver
  kconfig: tests: fix recursive inclusion unit test
  kbuild: teach kselftest-merge to find nested config files