ath25: switch to 4.14 kernel

Signed-off-by: Sergey Ryazanov <[email protected]>

target/linux/ath25/Makefile

@@ -12,7 +12,7 @@ BOARDNAME:=Atheros AR231x/AR5312
 FEATURES:=squashfs low_mem small_flash
 MAINTAINER:=Sergey Ryazanov <[email protected]>
 
-KERNEL_PATCHVER:=4.9
+KERNEL_PATCHVER:=4.14
 
 define Target/Description
 	Build firmware images for Atheros SoC boards