ARM: dts: keystone-k2l: fix mdio io start address

The K2L MDIO io space has different start address.
Hence, fix it to be 0x26200f00 according to TRM.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

arch/arm/boot/dts/k2l.dtsi

@@ -95,3 +95,7 @@ &spi2 {
        /* Pin muxed. Enabled and configured by Bootloader */
        status = "disabled";
 };
+
+&mdio {
+	reg = <0x26200f00 0x100>;
+};