imx-common: include mini-loader vf610m4bootldr

imx-common: include mini-loader vf610m4bootldr

Include vf610m4bootldr, a mini boot loader for the Cortex-M4 CPU
inside Freescale Vybrid SoC. The mini loader enables caches and
copies the pointer to the device tree from the platform specific
argument register (PERSISTENT_ARG1) to the Cortex-M4 r2 register,
where the Linux kernel expects the pointer. The mini loader hence
essentially takes over the parts of the m4boot command which can
not be done from the Cortex-A5 main CPU.