perf tools: Add map_groups to 'struct addr_location'

From there we can get al->mg->machine, so replace that field with the
more useful 'struct map_groups' that for now we're obtaining from
al->map->groups, and that is one thing getting into the way of maps
being fully shareable.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-4qdducrm32tgrjupcp0kjh1e@git.kernel.org


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