perf clang: Fix header include for LLVM >= 14

perf clang: Fix header include for LLVM >= 14

The header TargetRegistry.h has moved in LLVM/clang 14.

Committer notes:

The problem as noticed when building in ubuntu:22.04:

    90    98.61 ubuntu:22.04                  : FAIL gcc version 11.2.0 (Ubuntu 11.2.0-19ubuntu1)
      util/c++/clang.cpp:23:10: fatal error: llvm/Support/TargetRegistry.h: No such file or directory
         23 | #include "llvm/Support/TargetRegistry.h"
            |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      compilation terminated.

Fixed after applying this patch.

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Guilherme Amadio <amadio@gentoo.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://twitter.com/GuilhermeAmadio/status/1514970524232921088
Link: http://lore.kernel.org/lkml/Ylp0M/VYgHOxtcnF@gentoo.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>