[source] octeon: clean up image build code

[LEDE Commits]

jow pushed a commit to source.git, branch master:
https://git.lede-project.org/?p=source.git;a=commitdiff;h=fccc4298df79b72a5715910ac3a6f03c84f4949d

commit fccc4298df79b72a5715910ac3a6f03c84f4949d
Author: Jo-Philipp Wich <jo at mein.io>
AuthorDate: Fri Jul 29 15:03:19 2016 +0200

    octeon: clean up image build code
    
    Use the generic "sysupgrade-nand" build step to pack the sysupgrade file,
    it performs the same steps as the inline "tar-file" macro.
    
    Signed-off-by: Jo-Philipp Wich <jo at mein.io>
---
 target/linux/octeon/image/Makefile | 15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/target/linux/octeon/image/Makefile b/target/linux/octeon/image/Makefile
index e2d6539..3d1bdf7 100644
--- a/target/linux/octeon/image/Makefile
+++ b/target/linux/octeon/image/Makefile
@@ -7,25 +7,14 @@
 include $(TOPDIR)/rules.mk
 include $(INCLUDE_DIR)/image.mk
 
-DEVICE_VARS += KERNEL_PREFIX FILESYSTEMS
-
 define Device/Default
   PROFILES = Default $$(DEVICE_NAME)
+  BOARD_NAME := $(BOARD)
   KERNEL_NAME := vmlinux.elf
   KERNEL_INITRAMFS_NAME := vmlinux-initramfs.elf
   KERNEL := kernel-bin | strip-kernel | patch-cmdline
   IMAGES := sysupgrade.tar
-  FILESYSTEMS := squashfs
-  IMAGE/sysupgrade.tar := tar-file $$$$(FILESYSTEMS)
-endef
-
-define Build/tar-file
-	mkdir -p $(KDIR)/sysupgrade-$(DEVICE_NAME)/
-	echo "BOARD=$(BOARD)" > $(KDIR)/sysupgrade-$(DEVICE_NAME)/CONTROL
-	$(CP) $(KDIR_KERNEL_IMAGE) $(KDIR)/sysupgrade-$(DEVICE_NAME)/kernel
-	$(CP) $(KDIR)/root.$(1) $(KDIR)/sysupgrade-$(DEVICE_NAME)/root
-	(cd $(KDIR); $(TAR) cvf \
-		$@ sysupgrade-$(DEVICE_NAME))
+  IMAGE/sysupgrade.tar := sysupgrade-nand
 endef
 
 define Build/strip-kernel