ath79: nand: add 5.15 support for nand subtarget

Tested on GL.iNet E750

Signed-off-by: Koen Vandeputte <[email protected]>

target/linux/ath79/nand/target.mk

@@ -4,6 +4,8 @@ FEATURES += nand
 
 DEFAULT_PACKAGES += wpad-basic-wolfssl
 
+KERNEL_TESTING_PATCHVER:=5.15
+
 define Target/Description
 	Firmware for boards using Qualcomm Atheros, MIPS-based SoCs
 	in the ar72xx and subsequent series, with support for NAND flash