perf/x86/intel: Update event constraints for ICX

According to the latest event list, the event encoding 0xEF is only
available on the first 4 counters. Add it into the event constraints
table.

Fixes: 60176089

 ("perf/x86/intel: Add Icelake support")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1632842343-25862-1-git-send-email-kan.liang@linux.intel.com