--- zzzz-none-000/linux-4.9.218/arch/mips/boot/dts/brcm/Makefile	2020-04-02 15:20:41.000000000 +0000
+++ seale-7590ax-750/linux-4.9.218/arch/mips/boot/dts/brcm/Makefile	2023-03-29 10:59:06.000000000 +0000
@@ -33,10 +33,4 @@
 	bcm97425svmb.dtb \
 	bcm97435svmb.dtb
 
-obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
-
-# Force kbuild to make empty built-in.o if necessary
-obj-				+= dummy.o
-
-always				:= $(dtb-y)
-clean-files			:= *.dtb *.dtb.S
+obj-$(CONFIG_BUILTIN_DTB)	+= $(addsuffix .o, $(dtb-y))