perf parse-events: Fixes relating to no_value terms

perf parse-events: Fixes relating to no_value terms

A term may have no value in which case it is assumed to have a value
of 1. It doesn't just apply to alias/event terms so change the
parse_events_term__to_strbuf assert.

Commit 99e7138eb7897aa0 ("perf tools: Fail on using multiple bits long
terms without value") made it so that no_value terms could only be for a
single bit. Prior to commit 64199ae4b8a3 ("perf parse-events: Fix
propagation of term's no_value when cloning") this missed a test case
where config1 had no_value.

Fixes: 64199ae4b8a36038 ("perf parse-events: Fix propagation of term's no_value when cloning")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.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: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230901233949.2930562-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>