phy: marvell: add IGNORE COMPHY type

phy: marvell: add IGNORE COMPHY type

This type tells u-boot to preserve the COMPHY settings as is
it is usefull in situations where the COMPHY was initialized by
earlier firmware.
Note that IGNORE is different from UNCONNECTED since setting
UNCONNECTED type will disconnect the COMPHY in the COMPHY MUX
which is a desired behaviour

Signed-off-by: Yehuda Yitschak <yehuday@marvell.com>
Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Igal Liberman <igall@marvell.com>
Reviewed-by: Stefan Roese <sr@denx.de>