rockchip: binman: Include a compatible string in each configuration

Provide a compatible string in the config nodes that U-Boot can use to
help decide which configuration to use with SPL_LOAD_FIT_FULL=y and
FIT_BEST_MATCH=y.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>

arch/arm/dts/rockchip-u-boot.dtsi

@@ -145,6 +145,7 @@
 				fit,firmware = "op-tee", "u-boot";
 #endif
 				fit,loadables;
+				fit,compatible;
 			};
 		};
 	};