replace inline assembly WebRtcAecm_StoreAdaptiveChannelNeon  by intrinsics.

The modification only uses the unique part of the StoreAdaptiveChannel
 function. Pass byte to byte conformance test both on ARM32 and ARM64,
 and the single function performance is similar with original assembly
 version on different platforms. If not specified, the code is compiled
 by GCC 4.6.  The result is the "X version / C version" ratio, and the
 less is better.

| run 100k times             | cortex-a7 | cortex-a9 | cortex-a15 |
| use C as the base on each  |  (1.2Ghz) |  (1.0Ghz) |   (1.7Ghz) |
| CPU target                 |           |           |            |
|----------------------------+-----------+-----------+------------|
| Neon asm                   |    20.97% |    37.70% |     25.41% |
| Neon inline                |    36.93% |    51.80% |     38.14% |
| Neon intrinsics (GCC 4.6)  |    27.78% |    43.71% |     26.50% |
| Neon intrinsics (GCC 4.8)  |    27.16% |    38.22% |     26.87% |
| Neon intrinsics (LLVM 3.4) |    27.82% |    39.90% |     26.69% |

Change-Id: Ia55d8a268a70164b50676c604ae40b68fc183106

BUG=3580
R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/30029004

Patch from Zhongwei Yao <zhongwei.yao@arm.com>.

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7685 4adac7df-926f-26a2-2b94-8c16560cd09d