tools build: Make libperl opt-in rather than opt-out, deprecate

tools build: Make libperl opt-in rather than opt-out, deprecate

If libperl is installed then the perf tool build will build against
it. There appears to be limited interest in the scripting support for
perl so let's make it opt-in and deprecate it.

With this patch applied you need to add LIBPERL=1 to get libperl
support in perf - there is no warning if libperl is missing, but
building will fail if libperl is missing and the build has LIBPERL=1.
The perf version output is changed to:
```
$ perf version --build-options
perf version 6.17.rc3.g8eca69269947
                   aio: [ on  ]  # HAVE_AIO_SUPPORT
                   bpf: [ on  ]  # HAVE_LIBBPF_SUPPORT
         bpf_skeletons: [ on  ]  # HAVE_BPF_SKEL
            debuginfod: [ on  ]  # HAVE_DEBUGINFOD_SUPPORT
                 dwarf: [ on  ]  # HAVE_LIBDW_SUPPORT
    dwarf_getlocations: [ on  ]  # HAVE_LIBDW_SUPPORT
          dwarf-unwind: [ on  ]  # HAVE_DWARF_UNWIND_SUPPORT
              auxtrace: [ on  ]  # HAVE_AUXTRACE_SUPPORT
                libbfd: [ OFF ]  # HAVE_LIBBFD_SUPPORT ( tip: Deprecated, license incompatibility, use BUILD_NONDISTRO=1 and install binutils-dev[el] )
        libbpf-strings: [ on  ]  # HAVE_LIBBPF_STRINGS_SUPPORT
           libcapstone: [ on  ]  # HAVE_LIBCAPSTONE_SUPPORT
    libdw-dwarf-unwind: [ on  ]  # HAVE_LIBDW_SUPPORT
                libelf: [ on  ]  # HAVE_LIBELF_SUPPORT
               libnuma: [ on  ]  # HAVE_LIBNUMA_SUPPORT
            libopencsd: [ OFF ]  # HAVE_CSTRACE_SUPPORT
               libperl: [ OFF ]  # HAVE_LIBPERL_SUPPORT ( tip:
Deprecated, use LIBPERL=1 and install libperl-dev to build with it )
               libpfm4: [ on  ]  # HAVE_LIBPFM
             libpython: [ on  ]  # HAVE_LIBPYTHON_SUPPORT
              libslang: [ on  ]  # HAVE_SLANG_SUPPORT
         libtraceevent: [ on  ]  # HAVE_LIBTRACEEVENT
             libunwind: [ OFF ]  # HAVE_LIBUNWIND_SUPPORT ( tip:
Deprecated, use LIBUNWIND=1 and install libunwind-dev[el] to build
with it )
                  lzma: [ on  ]  # HAVE_LZMA_SUPPORT
numa_num_possible_cpus: [ on  ]  # HAVE_LIBNUMA_SUPPORT
                  zlib: [ on  ]  # HAVE_ZLIB_SUPPORT
                  zstd: [ on  ]  # HAVE_ZSTD_SUPPORT
```

i.e. there is a tip saying about deprecation and how to get support
back.

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <qmo@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Yuzhuo Jing <yuzhuo@google.com>
Link: https://lore.kernel.org/lkml/aMrk03gigBlGcYLK@x1/
Link: https://lore.kernel.org/lkml/CAP-5=fVX+bLBRJCiziDi_hBySgv2NFtDoghtpheSSxVAvvETGw@mail.gmail.com
[ Keep the pre-existing perl-ExtUtils-Embed hint for Fedora/RHEL systems ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>