ARM: dts: NSP: Enable SFP on bcm958625hr

Enable the SFP connected to port 5 of the switch and wire up all GPIOs
to the SFP cage. Because of a hardware limitation of the i2c controller
on the iProc SoCs which prevents large i2c (> 63 bytes) transactions to
work, we use the i2c-gpio interface instead, which does not have that
limitation. This allows us to read the SFP module EEPROM, which would
not be possible otherwise since it exceeds that size during a single
read transfer.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>