Add guards around neon code.

Missed the neon code in the copy bandwidths. Added guards and the
functionality to indicate that these are neon based benchmarks.

(cherry-pick of a67e53c2345eac337d24e4decaf4733c5314aff8.)

Change-Id: If0fae051c47979eb243681a3c994222cefaae826
1 file changed