perf parse-events: Use uintptr_t when casting numbers to pointers

To address these errors found when cross building from x86_64 to MIPS
little endian 32-bit:

    CC       /tmp/build/perf/util/parse-events-bison.o
  util/parse-events.y: In function 'parse_events_parse':
  util/parse-events.y:514:6: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
    514 |      (void *) $2, $6, $4);
        |      ^
  util/parse-events.y:531:7: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
    531 |       (void *) $2, NULL, $4)) {
        |       ^
  util/parse-events.y:547:6: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
    547 |      (void *) $2, $4, 0);
        |      ^
  util/parse-events.y:564:7: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
    564 |       (void *) $2, NULL, 0)) {
        |       ^

Fixes: cabbf268 ("perf parse: Before yyabort-ing free components")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Yonghong Song <yhs@fb.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>