siflower: add per-subtarget image makefile

Move SF19A2890 images into a separated .mk in preparation for
more subtargets.

Link: https://github.com/openwrt/openwrt/pull/17115
Signed-off-by: Chuanhong Guo <[email protected]>

target/linux/siflower/image/Makefile

@@ -2,27 +2,6 @@
 include $(TOPDIR)/rules.mk
 include $(INCLUDE_DIR)/image.mk
 
-KERNEL_LOADADDR := 0x80100000
-
-define Device/Default
-  PROFILES := Default
-  BLOCKSIZE := 64k
-  FILESYSTEMS := squashfs
-  DEVICE_DTS_DIR := ../dts
-  KERNEL := kernel-bin | append-dtb | lzma | uImage lzma
-  KERNEL_INITRAMFS := kernel-bin | append-dtb | lzma | uImage lzma
-  IMAGES := sysupgrade.bin
-  IMAGE/sysupgrade.bin = append-kernel | pad-to $$$$(BLOCKSIZE) | \
-	append-rootfs | pad-rootfs | append-metadata
-endef
-
-define Device/siflower_sf19a2890-evb
-  DEVICE_VENDOR := Siflower
-  DEVICE_MODEL := SF19A2890 EVB
-  BOARD_NAME := siflower,sf19a2890-evb
-  DEVICE_DTS := sf19a2890_evb
-  DEVICE_PACKAGES := kmod-switch-rtl8367b swconfig
-endef
-TARGET_DEVICES += siflower_sf19a2890-evb
+include $(SUBTARGET).mk
 
 $(eval $(call BuildImage))

target/linux/siflower/image/sf19a2890.mk

@@ -0,0 +1,22 @@
+KERNEL_LOADADDR := 0x80100000
+
+define Device/Default
+  PROFILES := Default
+  BLOCKSIZE := 64k
+  FILESYSTEMS := squashfs
+  DEVICE_DTS_DIR := ../dts
+  KERNEL := kernel-bin | append-dtb | lzma | uImage lzma
+  KERNEL_INITRAMFS := kernel-bin | append-dtb | lzma | uImage lzma
+  IMAGES := sysupgrade.bin
+  IMAGE/sysupgrade.bin = append-kernel | pad-to $$$$(BLOCKSIZE) | \
+	append-rootfs | pad-rootfs | append-metadata
+endef
+
+define Device/siflower_sf19a2890-evb
+  DEVICE_VENDOR := Siflower
+  DEVICE_MODEL := SF19A2890 EVB
+  BOARD_NAME := siflower,sf19a2890-evb
+  DEVICE_DTS := sf19a2890_evb
+  DEVICE_PACKAGES := kmod-switch-rtl8367b swconfig
+endef
+TARGET_DEVICES += siflower_sf19a2890-evb