perf kvm powerpc: Add missing rename opf pmu_have_event() to perf_pmus__have_event()

perf kvm powerpc: Add missing rename opf pmu_have_event() to perf_pmus__have_event()

Missed function rename from pmu_have_event to perf_pmus__have_event made
the perf build fail on powerpc.

Committer notes:

The perf_pmus__have_event() is declared in util/pmus.h, so use it
instead of by now needless util/pmu.h.

Fixes: 1eaf496ed386934f ("perf pmu: Separate pmu and pmus")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230530021433.3107580-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>