ARM: dts: NSP: Add new DT file for bcm958625hr

Create a new device tree file for the Broadcom Northstar Plus HR SVK.
This SVK is a smaller form factor, and thus only has 2 PCI slots and 1
UART.  Also, it has the ability to reboot via GPIO (instead of the
processor reset).

Signed-off-by: Jon Mason <jonmason@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>