ARM: dts: NSP: Add DT files for Meraki MX65 series

MX65 & MX65W Hardware info:
  - CPU: Broadcom BCM58625 Cortex A9 @ 1200Mhz
  - RAM: 2 GB (4 x 4Gb SK Hynix H5TC4G83CFR)
  - Storage: 1 GB (Micron MT29F8G08ABACA)
  - Networking: BCM58625 switch (2x 1GbE ports)
    2x Qualcomm QCA8337 switches (10x 1GbE ports total)
  - PSE: Broadcom BCM59111KMLG connected to LAN ports 11 & 12
  - USB: 1x USB2.0
  - Serial: Internal header
  - WLAN(MX65W Only): 2x Broadcom BCM43520KMLG on the PCI bus.

Note that a driver and firmware image for the BCM59111 PSE has been
released under GPL, but this is not present in the kernel.

Signed-off-by: Matthew Hagan <mnhagan88@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>