ARM: dts: at91: ksz9477_evb: fix port/phy validation

Latest drivers version requires phy-mode to be set. Otherwise we will
use "NA" mode and the switch driver will invalidate this port mode.

Fixes: 65ac79e1 ("net: dsa: microchip: add the phylink get_caps")
Signed-off-by: NOleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20220610081621.584393-1-o.rempel@pengutronix.deSigned-off-by: NJakub Kicinski <kuba@kernel.org>

arch/arm/boot/dts/at91-sama5d3_ksz9477_evb.dts

@@ -120,26 +120,31 @@
 			port@0 {
 				reg = <0>;
 				label = "lan1";
+				phy-mode = "internal";
 			};
 
 			port@1 {
 				reg = <1>;
 				label = "lan2";
+				phy-mode = "internal";
 			};
 
 			port@2 {
 				reg = <2>;
 				label = "lan3";
+				phy-mode = "internal";
 			};
 
 			port@3 {
 				reg = <3>;
 				label = "lan4";
+				phy-mode = "internal";
 			};
 
 			port@4 {
 				reg = <4>;
 				label = "lan5";
+				phy-mode = "internal";
 			};
 
 			port@5 {