Implements framework of perf kwork latency, which is used to report time
properties such as delay time and frequency.

Test cases:

  # perf kwork lat -h

   Usage: perf kwork latency [<options>]

      -C, --cpu <cpu>       list of cpus to profile
      -i, --input <file>    input file name
      -n, --name <name>     event name to profile
      -s, --sort <key[,key2...]>
                            sort by key(s): avg, max, count
          --time <str>      Time span for analysis (start,stop)

  # perf kwork lat -C 199
  Requested CPU 199 too large. Consider raising MAX_NR_CPUS
  Invalid cpu bitmap

  # perf kwork lat -i perf_no_exist.data
  failed to open perf_no_exist.data: No such file or directory

  # perf kwork lat -s avg1
    Error: Unknown --sort key: `avg1'

   Usage: perf kwork latency [<options>]

      -C, --cpu <cpu>       list of cpus to profile
      -i, --input <file>    input file name
      -n, --name <name>     event name to profile
      -s, --sort <key[,key2...]>
                            sort by key(s): avg, max, count
          --time <str>      Time span for analysis (start,stop)

  # perf kwork lat --time FFFF,
  Invalid time span

  # perf kwork lat

    Kwork Name                     | Cpu  | Avg delay     | Count    | Max delay     | Max delay start     | Max delay end       |
   --------------------------------------------------------------------------------------------------------------------------------
   --------------------------------------------------------------------------------------------------------------------------------
    INFO: 36.570% skipped events (31537 including 0 raise, 31537 entry, 0 exit)

Since there are no latency-enabled events, the output is empty.
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220709015033.38326-11-yangjihong1@huawei.com
[ Add {} for multiline if blocks ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>