ar71xx: switch to kernel 4.14

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

target/linux/ar71xx/Makefile

@@ -13,7 +13,7 @@ FEATURES:=usbgadget
 CPU_TYPE:=24kc
 SUBTARGETS:=generic tiny nand mikrotik
 
-KERNEL_PATCHVER:=4.9
+KERNEL_PATCHVER:=4.14
 
 include $(INCLUDE_DIR)/target.mk