fix: remove duplicated build-dtbs

make dtbs requires valid .config, but build-defconfig only works in debuild with patch applied.

Signed-off-by: ZHANG Yuntian <yt@radxa.com>

Author: RadxaYuntian

src/share/rsdk/infra-package/Makefile.linux.jsonnet

@@ -36,10 +36,6 @@ function(
 	build-defconfig: $(SRC-KERNEL)
 		$(KMAKE) $(KERNEL_DEFCONFIG)
 
-	.PHONY: build-dtbs
-	build-dtbs: $(SRC-KERNEL)
-		$(KMAKE) dtbs
-
 	.PHONY: build-modules
 	build-modules: $(SRC-KERNEL)
 		$(KMAKE) modules