Remove useless `neon:` clause. am: 563d9f467c

Original change: https://android-review.googlesource.com/c/platform/external/libopus/+/3009573

Change-Id: I16962a2f06d1f899d9456979bd1421a0096f6149
Signed-off-by: Automerger Merge Worker <[email protected]>