Introduce TARGET_linux-arm-compat makefile

Summary: A cleaner way to include all our cruft for removing optimizations for some "tricky" target products

Test Plan: I ensured the flags are being properly set. @randall.rushing: this is where you come in to test m7spr

Reviewers: randall.rushing, rlasalle15, Mustaavalkosta

Differential Revision: http://review.codefirex.com/D182

Change-Id: I9462c55354f15ab97366060ca70f308b28c0870c