perf parse-events: Handle fake PMUs in CPU terms

perf parse-events: Handle fake PMUs in CPU terms

The "Parsing of PMU event table metrics with fake PMUs" will test
metrics on machines/models that may be missing a PMU, in such a case
the fake_pmu should be used to avoid errors.

Metrics that get the cpumask from a different PMU, such as
"tsc/cpu=cpu_atom/", also need to be resilient in this test.

The parse_events_state fake_pmu is set when missing PMUs should be
ignored.

So that it can be queried, pass it to the config term functions, as well
as to get_config_cpu, then ignore failures when fake_pmu is set.

Some minor code refactoring to cut down on the indent and remove some
redundant checks.

Fixes: bd741d80dc65922c ("perf parse-events: Allow the cpu term to be a PMU or CPU range")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andreas Färber <afaerber@suse.de>
Cc: Caleb Biggers <caleb.biggers@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: linux-actions@lists.infradead.org
Cc: Manivannan Sadhasivam <mani@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Link: https://lore.kernel.org/r/20250818190416.145274-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>