Added MDIO multiplexer iproc DT node for Stingray, which contains
the child nodes of PCIe serdes, RGMII, SATA and USB phy MDIO slaves.
Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>