ARM: BCM5301X: Add DT for D-Link DIR-885L

It's device based on BCM47094 which is quite similar to BCM4709 except
for higher CPU frequency. This device has 2 flash memories, it boots
from serial one and stores firmware on NAND. Other than that we define
standard stuff like LEDs, buttons and UART.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>