uboot-imx

arm: mx6: add get_cpu_type()

Define get_cpu_type(). Reuse it in is_cpu_type().

Cc: Igor Grinberg <grinberg@compulab.co.il>
Cc: Stefano Babic <sbabic@denx.de>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>