Add a very minimalistic set of Northstar Plus Device Tree files which
describes the SoC and the BCM958625 implementation.  The perpherials
described are:

ARM Cortex A9 CPU
2 8250 UARTs
ARM GIC
PL310 L2 Cache
ARM A9 Global timer
Signed-off-by: NKapil Hali <kapilh@broadcom.com>
Signed-off-by: NJon Mason <jonmason@broadcom.com>
Reviewed-by: NRay Jui <rjui@broadcom.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>