Adding 'struct perf_hpp_fmt' into hpp callbacks, so commands can access
their private data.

It'll be handy for diff command in future to be able to access file
related data for each column.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-7vy2m18574b1bicoljn8e9lw@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>