Some headers are not used in building the tools directly, but instead to
generate tables that then gets source code included to do id->string and
string->id lookups for things like syscall flags and commands.

We were adding it directly to tools/include/ and this sometimes gets in
the way of building using system headers, lets untangle this a bit.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>