perf parse-events: Remove unused PE_KERNEL_PMU_EVENT token

perf parse-events: Remove unused PE_KERNEL_PMU_EVENT token

Removed by commit 70c90e4a6b2f ("perf parse-events: Avoid scanning
PMUs before parsing").

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230627181030.95608-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>