arm: vf610: Add Vybrid VF610 CPU support

This patch adds generic codes to support Freescale's Vybrid VF610 CPU.

It aligns Vybrid VF610 platform with i.MX platform. As there are
some differences between VF610 and i.MX platforms, the specific
codes are in the arch/arm/cpu/armv7/vf610 directory.

Signed-off-by: Alison Wang <b18965@freescale.com>
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>