Revert 8632 "Enable isac NEON building on Aarch64"

Breaks Chromium audio tests on Nexus 9.
http://build.chromium.org/p/chromium.webrtc.fyi/builders/Android%20Tests%20%28dbg%29%20%28L%20Nexus9%29/builds/1152/steps/content_browsertests/logs/stdio

It also actually broke already on our android_arm64 trybot in the CL:
http://build.chromium.org/p/tryserver.webrtc/builders/android_arm64/builds/3282
but I failed to double-check that (I guess I assumed it was flakiness since
that bot has been flaking a lot lately).

> Enable isac NEON building on Aarch64
> 
> Passed building isac_neon and modules_unittests on Android ARM64 and ARMv7.
> Passed modules_unittests with following filters:
>   --gtest_filter=FiltersTest*
>   --gtest_filter=LpcMaskingModelTest*
>   --gtest_filter=TransformTest*
>   --gtest_filter=FilterBanksTest*
> 
> WebRtcIsacfix_CalculateResidualEnergyNeon is not enabled due to Issue 4224.
> 
> BUG=4002
> R=andrew@webrtc.org, jridges@masque.com, kjellander@webrtc.org
> 
> Review URL: https://webrtc-codereview.appspot.com/39979004
> 
> Patch from Zhongwei Yao <zhongwei.yao@arm.com>.

TBR=zhongwei.yao@arm.com, andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/45559004

Cr-Commit-Position: refs/heads/master@{#8649}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8649 4adac7df-926f-26a2-2b94-8c16560cd09d
6 files changed