buildinfo: only set ro.build.product on non-unified devices

Change-Id: I5dccba2172dade3dacc55d832a2042fce306b5f5
core: Enable -mcpu=cortex-a9 flag for Cortex-A9 cpu variant

Change-Id: I9294a518bcdc21ccbae72eadd9f3c1a12982d028
core: armv7-a-neon.mk: Add missing endif

Change-Id: Id6f9c952d01d3c980115a52605d9c86038b3b5bd