Merge branch 'uapi-prep' of git://git.infradead.org/users/dhowells/linux-headers

Pull UAPI disintegration fixes from David Howells:
 "There are three main parts:

 (1) I found I needed some more fixups in the wake of testing Arm64
     (some asm/unistd.h files had weird guards that caused problems -
     mostly in arches for which I don't have a compiler) and some
     __KERNEL__ splitting needed to take place in Arm64.

 (2) I found that c6x was missing some __KERNEL__ guards in its
     asm/signal.h.  Mark Salter pointed me at a tree with a patch to
     remove that file entirely and use the asm-generic variant instead.

 (3) Lastly, m68k turned out to have a header installation problem due
     to it lacking a kvm_para.h file.

     The conditional installation bits for linux/kvm_para.h, linux/kvm.h
     and linux/a.out.h weren't very well specified - and didn't work if
     an arch didn't have the asm/ version of that file, but there *was*
     an asm-generic/ version.

     It seems the "ifneq $((wildcard ...),)" for each of those three
     headers in include/kernel/Kbuild is invoked twice during header
     installation, and the second time it matches on the just installed
     asm-generic/kvm_para.h file and thus incorrectly installs
     linux/kvm_para.h as well.

     Most arches actually have an asm/kvm_para.h, so this wasn't
     detectable in those."

* 'uapi-prep' of git://git.infradead.org/users/dhowells/linux-headers:
  UAPI: Fix conditional header installation handling (notably kvm_para.h on m68k)
  c6x: remove c6x signal.h
  UAPI: Split compound conditionals containing __KERNEL__ in Arm64
  UAPI: Fix the guards on various asm/unistd.h files
  c6x: make dsk6455 the default config