Revert "[depends] add m4 macros for compiler flag testing"

This reverts commit 6097ea3e9437c9cdef92c2f28e8cb8710af96017.
Revert "[depends] add neon and tegra switches"

This reverts commit ac39d8f1e48d0a875c411607d5c8d60fbd09ca3e.
Merge pull request #4816 from koying/fixdroiddepends

FIX: [droid] depends configure.in borked