Add --buildid-mmap option to enable build id in PERF_RECORD_MMAP2 events.

It will only work if there's kernel support for that and it disables
build id cache (implies --no-buildid).

It's also possible to enable it permanently via config option in
~/.perfconfig file:

  [record]
  build-id=mmap

Also added build_id bit in the verbose output for perf_event_attr:

  # perf record --buildid-mmap -vv
  ...
  perf_event_attr:
    type                             1
    size                             120
    ...
    build_id                         1

Adding also missing text_poke bit.

Committer testing:

  $ perf record -h build

   Usage: perf record [<options>] [<command>]
      or: perf record [<options>] -- <command> [<options>]

      -B, --no-buildid      do not collect buildids in perf.data
      -N, --no-buildid-cache
                            do not update the buildid cache
          --buildid-all     Record build-id of all DSOs regardless of hits
          --buildid-mmap    Record build-id in map events

  $

  $ perf record --buildid-mmap sleep 1
  Failed: no support to record build id in mmap events, update your kernel.
  $

After adding the needed kernel bits in a test kernel:

  $ perf record -vv --buildid-mmap sleep 1 |& grep -m1 build
  Enabling build id in mmap2 events.
  $ perf evlist -v
  cycles:u: size: 120, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, read_format: ID, disabled: 1, inherit: 1, exclude_kernel: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, build_id: 1
  $
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201214105457.543111-16-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>