Support for NXP's i.MX8QM SoC

NXP's i.MX8QM is an ARMv8 SoC with 2 clusters, 2 Cortex-A72
cores in one cluster and 4 Cortex-A53 in the other cluster,
and also has system controller (Cortex-M4) inside, documentation
can be found in below link:

https://www.nxp.com/products/processors-and-microcontrollers/


applications-processors/i.mx-applications-processors/i.mx-8-processors:IMX8-SERIES

This patch adds support for booting up SMP linux kernel (v4.9).

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>