Add support for ARMv7-A CPU architecture

This patchset adds support for the ARMv7-A CPU architecture.  Included in the patchset are:

- toolchain for armv7a (soft-float)
- config for kernel 3.14 and 3.2
- build system changes / refactor for new CPU arch
- Cortex-A9 QEMU virtual machine with working U-Boot and ONIE