perf hists: Move sort__need_collapse into struct perf_hpp_list

perf hists: Move sort__need_collapse into struct perf_hpp_list

Now we have sort dimensions private for struct hists, we need to make
dimension booleans hists specific as well.

Moving sort__need_collapse into struct perf_hpp_list.

Adding hists__has macro to easily access this info perf struct hists
object.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1462276488-26683-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>