Switch to the libperf mmap interface by calling directly
perf_evlist__mmap_ops() and removing perf's evlist__mmap_per_*
functions.

By switching to libperf perf_evlist__mmap() we need to operate over
'struct perf_mmap' in evlist__add_pollfd, so make the related changes
there.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191007125344.14268-22-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>