ar71xx: move nand device image definitions to a separate file

Signed-off-by: Felix Fietkau <nbd@nbd.name>

target/linux/ar71xx/image/Makefile

@@ -21,6 +21,9 @@ include ./tp-link.mk
 include ./ubnt.mk
 include ./generic.mk
 endif
+ifeq ($(SUBTARGET),nand)
+include ./nand.mk
+endif
 include ./legacy.mk
 
 define Build/netgear-squashfs
@@ -96,28 +99,4 @@ define Device/Default
   IMAGE/sysupgrade.bin = append-kernel $$$$(BLOCKSIZE) | append-rootfs | pad-rootfs | check-size $$$$(IMAGE_SIZE)
 endef
 
-ifeq ($(SUBTARGET),nand)
-
-define Build/MerakiNAND
-	-$(STAGING_DIR_HOST)/bin/mkmerakifw \
-		-B $(BOARDNAME) -s \
-		-i $@ \
-		-o $@.new
-	@mv $@.new $@
-endef
-
-define Device/mr18
-  BOARDNAME = MR18
-  BLOCKSIZE := 64k
-  CONSOLE = ttyS0,115200
-  MTDPARTS = ar934x-nfc:512k(nandloader)ro,8M(kernel),8M(recovery),113664k(ubi),128k@130944k(odm-caldata)ro
-  IMAGES := sysupgrade.tar
-  KERNEL := kernel-bin | patch-cmdline | MerakiNAND
-  KERNEL_INITRAMFS := kernel-bin | patch-cmdline | MerakiNAND
-  IMAGE/sysupgrade.tar := sysupgrade-nand
-endef
-TARGET_DEVICES += mr18
-
-endif # ifeq ($(SUBTARGET),nand)
-
 $(eval $(call BuildImage))

target/linux/ar71xx/image/nand.mk

@@ -0,0 +1,19 @@
+define Build/MerakiNAND
+	-$(STAGING_DIR_HOST)/bin/mkmerakifw \
+		-B $(BOARDNAME) -s \
+		-i $@ \
+		-o $@.new
+	@mv $@.new $@
+endef
+
+define Device/mr18
+  BOARDNAME = MR18
+  BLOCKSIZE := 64k
+  CONSOLE = ttyS0,115200
+  MTDPARTS = ar934x-nfc:512k(nandloader)ro,8M(kernel),8M(recovery),113664k(ubi),128k@130944k(odm-caldata)ro
+  IMAGES := sysupgrade.tar
+  KERNEL := kernel-bin | patch-cmdline | MerakiNAND
+  KERNEL_INITRAMFS := kernel-bin | patch-cmdline | MerakiNAND
+  IMAGE/sysupgrade.tar := sysupgrade-nand
+endef
+TARGET_DEVICES += mr18