[openwrt/openwrt] mvebu: add Linux 5.15 as testing kernel

[LEDE Commits]

rsalvaterra pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/03f41b1eb2f15ab06d5800274be6a67c64e2a629

commit 03f41b1eb2f15ab06d5800274be6a67c64e2a629
Author: Rui Salvaterra <rsalvaterra at gmail.com>
AuthorDate: Mon Apr 4 16:06:16 2022 +0100

    mvebu: add Linux 5.15 as testing kernel
    
    Run-tested on the cortexa9 subtarget (Turris Omnia).
    
    Signed-off-by: Rui Salvaterra <rsalvaterra at gmail.com>
---
 target/linux/mvebu/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/linux/mvebu/Makefile b/target/linux/mvebu/Makefile
index ce43c8652d..6a1e0f63f7 100644
--- a/target/linux/mvebu/Makefile
+++ b/target/linux/mvebu/Makefile
@@ -10,6 +10,7 @@ FEATURES:=fpu usb pci pcie gpio nand squashfs ramdisk boot-part rootfs-part lega
 SUBTARGETS:=cortexa9 cortexa53 cortexa72
 
 KERNEL_PATCHVER:=5.10
+KERNEL_TESTING_PATCHVER:=5.15
 
 include $(INCLUDE_DIR)/target.mk