BoardConfig: bring back disable arm pie flag.

This commit needs these following alternate gcc-4.7 toolchains to function:

https://github.com/Team-Hydra/prebuilts_gcc_linux-x86_arm_arm-linux-androideabi-4.7
https://github.com/Team-Hydra/prebuilts_gcc_linux-x86_arm_arm-eabi-4.7