phy: mvebu-cp110-comphy: Add USB3 host/device support

Add USB3 host/device support by adding the right entries in the COMPHY
modes table. A new macro is created to instantiate a "generic" mode
ie. not an Ethernet one. This macro will be re-used when adding SATA
support.

Signed-off-by: Grzegorz Jaszczyk <jaz@semihalf.com>
[miquel.raynal@bootlin.com: adapt the content to the mainline driver]
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>