x86, lib: Add wbinvd smp helpers

x86, lib: Add wbinvd smp helpers

commit a7b480e7f30b3813353ec009f10f2ac7a6669f3b upstream.

Add wbinvd_on_cpu and wbinvd_on_all_cpus stubs for executing wbinvd on a
particular CPU.

[ hpa: renamed lib/smp.c to lib/cache-smp.c ]
[ hpa: wbinvd_on_all_cpus() returns int, but wbinvd() returns
  void.  Thus, the former cannot be a macro for the latter,
  replace with an inline function. ]

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1264172467-25155-2-git-send-email-bp@amd64.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>