Implements workqueue trace bpf function.

Test cases:

  # perf kwork -k workqueue lat -b
  Starting trace, Hit <Ctrl+C> to stop and report
  ^C
    Kwork Name                     | Cpu  | Avg delay     | Count     | Max delay     | Max delay start     | Max delay end       |
   --------------------------------------------------------------------------------------------------------------------------------
    (w)addrconf_verify_work        | 0002 |      5.856 ms |         1 |      5.856 ms |     111994.634313 s |     111994.640169 s |
    (w)vmstat_update               | 0001 |      1.247 ms |         1 |      1.247 ms |     111996.462651 s |     111996.463899 s |
    (w)neigh_periodic_work         | 0001 |      1.183 ms |         1 |      1.183 ms |     111996.462789 s |     111996.463973 s |
    (w)neigh_managed_work          | 0001 |      0.989 ms |         2 |      1.635 ms |     111996.462820 s |     111996.464455 s |
    (w)wb_workfn                   | 0000 |      0.667 ms |         1 |      0.667 ms |     111996.384273 s |     111996.384940 s |
    (w)bpf_prog_free_deferred      | 0001 |      0.495 ms |         1 |      0.495 ms |     111986.314201 s |     111986.314696 s |
    (w)mix_interrupt_randomness    | 0002 |      0.421 ms |         6 |      0.749 ms |     111995.927750 s |     111995.928499 s |
    (w)vmstat_shepherd             | 0000 |      0.374 ms |         2 |      0.385 ms |     111991.265242 s |     111991.265627 s |
    (w)e1000_watchdog              | 0002 |      0.356 ms |         5 |      0.390 ms |     111994.528380 s |     111994.528770 s |
    (w)vmstat_update               | 0000 |      0.231 ms |         2 |      0.365 ms |     111996.384407 s |     111996.384772 s |
    (w)flush_to_ldisc              | 0006 |      0.165 ms |         1 |      0.165 ms |     111995.930606 s |     111995.930771 s |
    (w)flush_to_ldisc              | 0000 |      0.094 ms |         2 |      0.095 ms |     111996.460453 s |     111996.460548 s |
   --------------------------------------------------------------------------------------------------------------------------------

  # perf kwork -k workqueue rep -b
  Starting trace, Hit <Ctrl+C> to stop and report
  ^C
    Kwork Name                     | Cpu  | Total Runtime | Count     | Max runtime   | Max runtime start   | Max runtime end     |
   --------------------------------------------------------------------------------------------------------------------------------
    (w)e1000_watchdog              | 0002 |      0.627 ms |         2 |      0.324 ms |     112002.720665 s |     112002.720989 s |
    (w)flush_to_ldisc              | 0007 |      0.598 ms |         2 |      0.534 ms |     112000.875226 s |     112000.875761 s |
    (w)wq_barrier_func             | 0007 |      0.492 ms |         1 |      0.492 ms |     112000.876981 s |     112000.877473 s |
    (w)flush_to_ldisc              | 0007 |      0.281 ms |         1 |      0.281 ms |     112005.826882 s |     112005.827163 s |
    (w)mix_interrupt_randomness    | 0002 |      0.229 ms |         3 |      0.102 ms |     112005.825671 s |     112005.825774 s |
    (w)vmstat_shepherd             | 0000 |      0.202 ms |         1 |      0.202 ms |     112001.504511 s |     112001.504713 s |
    (w)bpf_prog_free_deferred      | 0001 |      0.181 ms |         1 |      0.181 ms |     112000.883251 s |     112000.883432 s |
    (w)wb_workfn                   | 0007 |      0.130 ms |         1 |      0.130 ms |     112001.505195 s |     112001.505325 s |
    (w)vmstat_update               | 0000 |      0.053 ms |         1 |      0.053 ms |     112001.504763 s |     112001.504815 s |
   --------------------------------------------------------------------------------------------------------------------------------
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.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/20220709015033.38326-18-yangjihong1@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>