perf tools: Remove tools/perf/util/include/linux/const.h

Not used anymore, remove one more file referencing kernel sources, i.e.
outside of tools/

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ykfjt3t8l0npxfwmekiwwyu6@git.kernel.org


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