ARM: dts: am335x-evm: Fix PHY mode for ethernet

The PHY must add both tx and rx delay and not only on the tx clock.
The board uses AR8031_AL1A PHY where the rx delay is enabled by default,
the tx dealy is disabled.

The reason why rgmii-txid worked because the rx delay was not disabled by
the driver so essentially we ended up with rgmii-id PHY mode.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am335x-evm.dts

@@ -729,7 +729,7 @@ ethphy0: ethernet-phy@0 {
 
 &cpsw_emac0 {
 	phy-handle = <&ethphy0>;
-	phy-mode = "rgmii-txid";
+	phy-mode = "rgmii-id";
 };
 
 &tscadc {