phy: mvebu-cp110-comphy: Allow non-Ethernet modes to be configured

The COMPHY can configure the SERDES lanes in several non-Ethernet
modes: SATA, USB3, PCIe. Drop the condition limiting the driver to
Ethernet modes only before adding support for more.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>