ARM: dts: NSP: Add crypto (SPU) to dtsi

Adds crypto hardware (SPU) to Northstar Plus device tree file.

Signed-off-by: Steve Lin <steven.lin1@broadcom.com>
Acked-by: Jon Mason <jon.mason@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>