ramips: add support for Allnet ALL-PR4014P

ramips: add support for Allnet ALL-PR4014P

Hardware
--------
CPU:     MediaTek MT7621
RAM:     128M DDR3 (NANYA NT5CC64M16GP-DI)
FLASH:   8MB SPI-NOR (Macronix MX25L6405D)
PoE-PSE: Microsemi PD69104B1
PoE-PD:  TI TPS2379
UART:    57600 8N1 3.3V
         Pinout is silkscreened next to header
         Don't connect VCC / 3.3V!

Installation
------------
Upload the OpenWrt sysupgrade image using the Update page in the
web-interface of the Router. Make sure you use the correct mask
(Firmware, not Bootloader!).

Be patient. This process is very slow and can take up to 5 minutes.

Signed-off-by: David Bauer <mail@david-bauer.net>