Remove useless `neon:` clause. am: 62a3b8ca4a

Original change: https://android-review.googlesource.com/c/platform/external/libmpeg2/+/3010320

Change-Id: I274fa12c10d01f2e9c681c5252615aa0fee6636d
Signed-off-by: Automerger Merge Worker <[email protected]>