[openwrt/openwrt] mediatek: switch to 5.15

[LEDE Commits]

981213 pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/c283defa886f790ca3ab1c54f50b1a36d33d50ba

commit c283defa886f790ca3ab1c54f50b1a36d33d50ba
Author: Chuanhong Guo <gch981213 at gmail.com>
AuthorDate: Thu Apr 14 12:45:01 2022 +0800

    mediatek: switch to 5.15
    
    the SPI-NAND driver switch breaks dts compatibility. It's too much work
    to backport all ECC framework support to 5.10 so let's switch the target
    to 5.15 instead.
    
    Signed-off-by: Chuanhong Guo <gch981213 at gmail.com>
---
 target/linux/mediatek/Makefile | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/target/linux/mediatek/Makefile b/target/linux/mediatek/Makefile
index 2b4f240429..da3cf18cf6 100644
--- a/target/linux/mediatek/Makefile
+++ b/target/linux/mediatek/Makefile
@@ -8,8 +8,7 @@ BOARDNAME:=MediaTek Ralink ARM
 SUBTARGETS:=mt7622 mt7623 mt7629
 FEATURES:=dt-overlay emmc fpu gpio nand pci pcie rootfs-part separate_ramdisk squashfs usb
 
-KERNEL_PATCHVER:=5.10
-KERNEL_TESTING_PATCHVER:=5.15
+KERNEL_PATCHVER:=5.15
 
 include $(INCLUDE_DIR)/target.mk
 DEFAULT_PACKAGES += \