[openwrt/openwrt] ath79: add missing UBNT_REVISION

[LEDE Commits]

blocktrron pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/cfa670bf16afc10855ca0adec50a807b684ba6a7

commit cfa670bf16afc10855ca0adec50a807b684ba6a7
Author: Nick Hainke <vincent at systemli.org>
AuthorDate: Sun Dec 26 11:59:44 2021 +0100

    ath79: add missing UBNT_REVISION
    
    The UBNT_REVISION was already added for the ubnt-xw target because:
    
      U-boot bootloader on M-XW devices expects factory image revision
      version in specific format. On airOS v6.1.7 with `U-Boot 1.1.4-s1039
      (May 24 2017 - 15:58:18)` bootloader checks if the revision major(?)
      number is actually a number, but in currently generated images there's
      OpenWrt text and so the check fails
    
      ...
    
      By placing arbitrary correct number first in major version, we make the
      bootloader happy and we can flash factory images over TFTP again.
    
      commit d42a7c469909 ("ath79: ubnt-m-xw: Fix factory image flashing using TFTP recovery method")
    
    Fixes errors in the form of (tftp flashing):
      sent DATA <block=8577, 412 bytes>
      received ERROR <code=2, msg=Firmware check failed>
      Error code 2: Firmware check failed
    
    The missing UBNT_REVISION was not noticed before, since the
    UBNT_REVISION field for the ubnt-xm target was also set to:
      "42.OpenWrt-..."
    Probably, UBNT_REVISION for the ubnt-xm target was set by the ubnt-xw
    and was never overridden somewhere else. However, it is missing and
    should be part of the ubnt-xm device.
    
    Signed-off-by: Nick Hainke <vincent at systemli.org>
---
 target/linux/ath79/image/generic-ubnt.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/linux/ath79/image/generic-ubnt.mk b/target/linux/ath79/image/generic-ubnt.mk
index 3888e1652b..bb5eaa5458 100644
--- a/target/linux/ath79/image/generic-ubnt.mk
+++ b/target/linux/ath79/image/generic-ubnt.mk
@@ -103,6 +103,7 @@ define Device/ubnt-xm
   IMAGE_SIZE := 7448k
   UBNT_BOARD := XM
   UBNT_CHIP := ar7240
+  UBNT_REVISION := 42.$(UBNT_REVISION)
   UBNT_TYPE := XM
   UBNT_VERSION := 6.0.0
   KERNEL := kernel-bin | append-dtb | relocate-kernel | lzma | uImage lzma