perf ftrace: Add 'profile' command

The 'perf ftrace profile' command is to get function execution profiles
using function-graph tracer so that users can see the total, average,
max execution time as well as the number of invocations easily.

The following is a profile for the perf_event_open syscall.

  $ sudo perf ftrace profile -G __x64_sys_perf_event_open -- \
    perf stat -e cycles -C1 true 2> /dev/null | head
  # Total (us)   Avg (us)   Max (us)      Count   Function
        65.611     65.611     65.611          1   __x64_sys_perf_event_open
        30.527     30.527     30.527          1   anon_inode_getfile
        30.260     30.260     30.260          1   __anon_inode_getfile
        29.700     29.700     29.700          1   alloc_file_pseudo
        17.578     17.578     17.578          1   d_alloc_pseudo
        17.382     17.382     17.382          1   __d_alloc
        16.738     16.738     16.738          1   kmem_cache_alloc_lru
        15.686     15.686     15.686          1   perf_event_alloc
        14.012      7.006     11.264          2   obj_cgroup_charge
  #

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Changbin Du <changbin.du@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/lkml/20240729004127.238611-4-namhyung@kernel.org


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