[arm64] Add missing simulator instrumentation counter.

Change-Id: Id6163e68877554d67ae447e6607fb6a5944ac8c9
Reviewed-on: https://chromium-review.googlesource.com/1120166Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Cr-Commit-Position: refs/heads/master@{#54242}

src/arm64/instrument-arm64.cc

@@ -69,6 +69,7 @@ static const CounterDescriptor kCounterList[] = {
     {"Logical DP", Gauge},
     {"Other Int DP", Gauge},
     {"FP DP", Gauge},
+    {"NEON", Gauge},
 
     {"Conditional Select", Gauge},
     {"Conditional Compare", Gauge},