arm64: dts: marvell: clearfog-gt-8k: set SFP power limit

The Clearfog GT-8K board is capable of supplying power up to 2W to SFP
modules. Make that explicit in the device-tree. Without this property
current kernel does not allow SFP modules that require more than 1W.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>