ARM: at91/dt: describe rgmii ethernet phy connected to sama5d3xek boards

Add ethernet-phy nodes and specify phy interrupt (connected to pin PB25)
and board specific timing configs.

Atmel has two different HW designs for its CPU modules: the first one
(produced by Embest) is connecting PHYAD[0-2] pins to pull up resistors
and the other one (produced by Ronetix) is connecting PHYAD0 to a pull up
resistor and PHYAD[1-2] to pull down resistors.
As a result, Ronetix design will have its PHY available at address 0x1 and
Embest design at 0x7.
By defining both phys we're letting the phy core detect the one actually
available on the MDIO bus.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Tested-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91: remove phy fixup for sama5d3xek boards

These board specific delays are now configured through micrel's specific
DT bindings (see Documentation/devicetree/bindings/net/micrel-ksz9021.txt).

Remove this phy fixup registration from sama5 DT machine file to keep it
as generic as possible.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Tested-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>