realtek: merge duplicated DGS-1210 recipes

The D-Link DGS-1210 device series currently has supported devices with
both RTL838x and RTL839x SoCs. An image build recipe has been defined in
both subtarget makefiles, but these are mostly identical, save for the
SOC variable.

Move the SOC variable from the DGS-1210 build recipes to the applicable
devices, and put the remaining duplicate code in a shared Makefile.

Signed-off-by: Sander Vanheule <sander@svanheule.net>

target/linux/realtek/image/common.mk

@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+define Build/d-link_dgs-1210
+  IMAGE_SIZE := 13824k
+  DEVICE_VENDOR := D-Link
+  DLINK_KERNEL_PART_SIZE := 1572864
+  KERNEL := kernel-bin | append-dtb | gzip | uImage gzip | dlink-cameo
+  CAMEO_KERNEL_PART := 2
+  CAMEO_ROOTFS_PART := 3
+  CAMEO_CUSTOMER_SIGNATURE := 2
+  CAMEO_BOARD_VERSION := 32
+  IMAGES += factory_image1.bin
+  IMAGE/factory_image1.bin := append-kernel | pad-to 64k | \
+        append-rootfs | pad-rootfs | pad-to 16 | check-size | \
+        dlink-version | dlink-headers
+endef

target/linux/realtek/image/rtl838x.mk

@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
+include ./common.mk
 
 define Device/allnet_all-sg8208m
   SOC := rtl8382
@@ -11,24 +12,8 @@ define Device/allnet_all-sg8208m
 endef
 TARGET_DEVICES += allnet_all-sg8208m
 
-define Device/d-link_dgs-1210
-  SOC := rtl8382
-  IMAGE_SIZE := 13824k
-  DEVICE_VENDOR := D-Link
-  DLINK_KERNEL_PART_SIZE := 1572864
-  KERNEL := kernel-bin | append-dtb | gzip | uImage gzip | dlink-cameo
-  CAMEO_KERNEL_PART := 2
-  CAMEO_ROOTFS_PART := 3
-  CAMEO_CUSTOMER_SIGNATURE := 2
-  CAMEO_BOARD_VERSION := 32
-  IMAGES += factory_image1.bin
-  IMAGE/factory_image1.bin := append-kernel | pad-to 64k | \
-	append-rootfs | pad-rootfs | pad-to 16 | check-size | \
-	dlink-version | dlink-headers
-endef
-
 define Device/d-link_dgs-1210-10mp-f
-  $(Device/d-link_dgs-1210)
+  $(Build/d-link_dgs-1210)
   SOC := rtl8380
   DEVICE_MODEL := DGS-1210-10MP
   DEVICE_VARIANT := F
@@ -37,26 +22,30 @@ endef
 TARGET_DEVICES += d-link_dgs-1210-10mp-f
 
 define Device/d-link_dgs-1210-10p
-  $(Device/d-link_dgs-1210)
+  $(Build/d-link_dgs-1210)
+  SOC := rtl8382
   DEVICE_MODEL := DGS-1210-10P
   DEVICE_PACKAGES += lua-rs232
 endef
 TARGET_DEVICES += d-link_dgs-1210-10p
 
 define Device/d-link_dgs-1210-16
-  $(Device/d-link_dgs-1210)
+  $(Build/d-link_dgs-1210)
+  SOC := rtl8382
   DEVICE_MODEL := DGS-1210-16
 endef
 TARGET_DEVICES += d-link_dgs-1210-16
 
 define Device/d-link_dgs-1210-20
-  $(Device/d-link_dgs-1210)
+  $(Build/d-link_dgs-1210)
+  SOC := rtl8382
   DEVICE_MODEL := DGS-1210-20
 endef
 TARGET_DEVICES += d-link_dgs-1210-20
 
 define Device/d-link_dgs-1210-28
-  $(Device/d-link_dgs-1210)
+  $(Build/d-link_dgs-1210)
+  SOC := rtl8382
   DEVICE_MODEL := DGS-1210-28
 endef
 TARGET_DEVICES += d-link_dgs-1210-28

target/linux/realtek/image/rtl839x.mk

@@ -1,23 +1,10 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
-define Device/d-link_dgs-1210
+include ./common.mk
-  SOC := rtl8393
-  IMAGE_SIZE := 13824k
-  DEVICE_VENDOR := D-Link
-  DLINK_KERNEL_PART_SIZE := 1572864
-  KERNEL := kernel-bin | append-dtb | gzip | uImage gzip | dlink-cameo
-  CAMEO_KERNEL_PART := 2
-  CAMEO_ROOTFS_PART := 3
-  CAMEO_CUSTOMER_SIGNATURE := 2
-  CAMEO_BOARD_VERSION := 32
-  IMAGES += factory_image1.bin
-  IMAGE/factory_image1.bin := append-kernel | pad-to 64k | \
-        append-rootfs | pad-rootfs | pad-to 16 | check-size | \
-        dlink-version | dlink-headers
-endef
 
 define Device/d-link_dgs-1210-52
-  $(Device/d-link_dgs-1210)
+  $(Build/d-link_dgs-1210)
+  SOC := rtl8393
   DEVICE_MODEL := DGS-1210-52
 endef
 TARGET_DEVICES += d-link_dgs-1210-52