tools headers uapi: Sync kvm.h copy

To pick up the changes introduced in:

  6fbbde9a ("KVM: x86: Control guest reads of MSR_PLATFORM_INFO")

That is not yet used in tools such as 'perf trace'.

The type of the change in this file, a simple integer parameter to the
KVM_CHECK_EXTENSION ioctl should be easier to implement tho, adding to
the libbeauty TODO list.

This silences this perf build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/kvm.h' differs from latest version at 'include/uapi/linux/kvm.h'
  diff -u tools/include/uapi/linux/kvm.h include/uapi/linux/kvm.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Drew Schmitt <dasch@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-67h1bio5bihi1q6dy7hgwwx8@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>