mips: dts: econet: fix EN751221 core type

In fact, it is a multi-threaded MIPS34Kc, not a single-threaded MIPS24Kc.

Fixes: 0ec4887 ("mips: dts: Add EcoNet DTS with EN751221 and SmartFiber XP8421-B board")
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

Author: abajk

arch/mips/boot/dts/econet/en751221.dtsi

@@ -18,7 +18,7 @@
 
 		cpu@0 {
 			device_type = "cpu";
-			compatible = "mips,mips24KEc";
+			compatible = "mips,mips34Kc";
 			reg = <0>;
 		};
 	};