ARM: perf: remove unused armpmu_get_max_events

armpmu_get_max_events is only called from perf_num_counters, so we can
inline it there. It existed as a separate entity as a hangover from
the original perf-based oprofile implementation.

Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm/include/asm/perf_event.h

@@ -32,7 +32,4 @@ enum arm_perf_pmu_ids {
 extern enum arm_perf_pmu_ids
 armpmu_get_pmu_id(void);
 
-extern int
-armpmu_get_max_events(void);
-
 #endif /* __ARM_PERF_EVENT_H__ */