ramips: fix WHR-1166D WAN port

By adding the ICPlus IP1001 phy driver an already set RGMII delay mode
is reset during driver load.

Set the rgmii rx delay to fix corrupt/no packages in case the WAN port
negotiates to 1000MBit.

Fixes: FS#670

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/ramips/dts/WHR-1166D.dts

@@ -145,7 +145,7 @@
 
 		phy5: ethernet-phy@5 {
 			reg = <5>;
-			phy-mode = "rgmii";
+			phy-mode = "rgmii-rxid";
 		};
 	};
 };