ramips: bdcom-wap2100: Set firmware partition format to denx,uimage

Specify firmware partition format to denx,uimage in compatible DTS property.

 2 uimage-fw partitions found on MTD device firmware
 Creating 2 MTD partitions on "firmware":
 0x000000000000-0x00000017f72b : "kernel"
 0x00000017f72b-0x000000f70000 : "rootfs"

Signed-off-by: Petr Štetiar <ynezz@true.cz>

target/linux/ramips/dts/BDCOM-WAP2100-SK.dts

@@ -89,6 +89,7 @@
 			};
 
 			partition@50000 {
+				compatible = "denx,uimage";
 				label = "firmware";
 				reg = <0x50000 0xf70000>;
 			};