tools arch amd ibs: Sync ibs.h with the kernel sources

To pick up the changes from:

  861c6b11 ("x86/platform/amd: Add standard header guards to <asm/amd/ibs.h>")

A small change to tools/perf/check-headers.sh was made to cope with the
move of this header done in:

  3846389c ("x86/platform/amd: Move the <asm/amd-ibs.h> header to <asm/amd/ibs.h>")

That don't result in any changes in the tools, just address this perf
build warning:

Warning: Kernel ABI header differences:
  diff -u tools/arch/x86/include/asm/amd/ibs.h arch/x86/include/asm/amd/ibs.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/aEtCi0pup5FEwnzn@x1


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