ARM: dts: imx6qdl-sr-som: fix some cubox-i platforms

The PHY address bit 2 is configured by the LED pin. Attaching a LED
to this pin is not sufficient to guarantee this configuration pin is
correctly read. This leads to some platforms having their PHY at
address 0 and others at address 4.

If there is no phy-handle specified, the FEC driver will scan the PHY
bus for a PHY and use that. Consequently, adding the DT configuration
of the PHY and the phy properties to the FEC driver broke some boards.

Fix this by removing the phy-handle property, and listing two PHY
entries for both possible PHY addresses, so that the DT configuration
for the PHY can be found by the PHY driver.

Fixes: 86b08bd5 ("ARM: dts: imx6-sr-som: add ethernet PHY configuration")
Reported-by: Christoph Mattheis <christoph.mattheis@arcor.de>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>