There are functions using __u64, so we need to have the linux/types.h
header otherwise we'll break when its not included before api/io.h.

Fixes: e95770af ("tools api: Add a lightweight buffered reading api")
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZWjDPL+IzPPsuC3X@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>