arch/arm64/boot/dts/broadcom/Makefile - third_party/linux - Git at Google

 dtb-$(CONFIG_ARCH_BCM2835) += bcm2837-rpi-3-b.dtb

 dts-dirs	+= northstar2
 dts-dirs	+= stingray
 always		:= $(dtb-y)
 subdir-y	:= $(dts-dirs)
 clean-files	:= *.dtb
	dtb-$(CONFIG_ARCH_BCM2835) += bcm2837-rpi-3-b.dtb

	dts-dirs += northstar2
	dts-dirs += stingray
	always := $(dtb-y)
	subdir-y := $(dts-dirs)
	clean-files := *.dtb