Fixup armv8-a building, and make multiarch builds work

Change-Id: Ica6c855a77cb14a2c96682f6c7bf5bdae9a06970
Fix derp in new v7a-neon config

This breaks teh build. fixit

Change-Id: I0bc7cb7090c68628673afe9ccf03ea49cc875fd6
build: Use ARM mode for arm32 builds

thumb mode does NOT work on some codecs. ARM all the way

Change-Id: Ib92d9fc718388e5e0340534cef1eeba986587653
ffmpeg: Fix variable collisions

 * We need some undefs here because FFMPEG wants these values to equal
   either 1 or 0, while Bionic just defines it to nothing.

Change-Id: I2505d4c077db41b3fa61af5a9b2c83491f0b9b88