Merge 7580 "Build fix for MIPS32R6."

> Build fix for MIPS32R6.
> 
> Exclude MIPS optimizations for MIPS32R6 build since some of the instructions
> are not supported. This is temporary fix, until the MIPS32R6 code is added.
> 
> R=andrew@webrtc.org
> 
> Review URL: https://webrtc-codereview.appspot.com/25989004
> 
> Patch from Ljubomir Papuga <lpapuga@mips.com>.

TBR=lpapuga@mips.com
BUG=chromium:438351

Review URL: https://webrtc-codereview.appspot.com/31079004

git-svn-id: http://webrtc.googlecode.com/svn/branches/39/webrtc@7784 4adac7df-926f-26a2-2b94-8c16560cd09d
4 files changed