What DEVICE_DTS_CONFIG's value mean?

I'm learning to add support for new board. I'm reading https://github.com/openwrt/openwrt/blob/master/target/linux/ipq40xx/image/generic.mk and find:

define Device/openmesh_a62
	$(call Device/FitImageLzma)
	DEVICE_VENDOR := OpenMesh
	DEVICE_MODEL := A62
	SOC := qcom-ipq4019
	DEVICE_DTS_CONFIG := config@om.a62
	BLOCKSIZE := 64k
	KERNEL = kernel-bin | lzma | fit lzma $$(KDIR)/image-$$(DEVICE_DTS).dtb | pad-to $$(BLOCKSIZE)
	IMAGE_SIZE := 15552k
	IMAGES += factory.bin
	IMAGE/factory.bin := append-rootfs | pad-rootfs | openmesh-image ce_type=A62
	IMAGE/sysupgrade.bin/squashfs := append-rootfs | pad-rootfs | sysupgrade-tar rootfs=$$$$@ | append-metadata
	DEVICE_PACKAGES := ath10k-firmware-qca9888-ct
endef
TARGET_DEVICES += openmesh_a62

I don't understand the value config@om.a62 of DEVICE_DTS_CONFIG. Is om.a62 corresponding with any file, or how to know what to put in there?