perf map: Move maj/min/ino/ino_generation to separate struct

perf map: Move maj/min/ino/ino_generation to separate struct

And this patch highlights where these fields are being used: in the sort
order where it uses it to compare maps and classify samples taking into
account not just the DSO, but those DSO id fields.

I think these should be used to differentiate DSOs with the same name
but different 'struct dso_id' fields, i.e. these fields should move to
'struct dso' and then be used as part of the key when doing lookups for
DSOs, in addition to the DSO name.

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-8v5isitqy0dup47nnwkpc80f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>