oxnas: use vendor_model scheme for ox810se

Most newer targets have been converted to consistently use
vendor_model scheme for device definitions/image names, ox820 is
using it as well, so let's just convert ox810se for consistency.

While at it, use generic setup for DEVICE_DTS and add SUPPORTED_DEVICES.
The latter have been introduced for ox820 already in
cf78961 ("oxnas: enable image metadata by setting SUPPORTED_DEVICES")

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/oxnas/image/ox810se.mk

@@ -6,15 +6,16 @@ define Device/Default
   KERNEL_INSTALL := 1
   FILESYSTEMS := squashfs ext4
   PROFILES := Default
+  SUPPORTED_DEVICES := $(subst _,$(comma),$(1))
+  DEVICE_DTS := ox810se-$(subst _,-,$(1))
   IMAGES := sysupgrade.tar
   IMAGE/sysupgrade.tar := sysupgrade-tar | append-metadata
 endef
 
-define Device/wd-mbwe
-  DEVICE_DTS := ox810se-wd-mbwe
+define Device/wd_mbwe
   DEVICE_VENDOR := Western Digital
   DEVICE_MODEL := My Book
   DEVICE_VARIANT := World Edition
   KERNEL := kernel-bin | append-dtb | uImage none
 endef
-TARGET_DEVICES += wd-mbwe
+TARGET_DEVICES += wd_mbwe