ar7: switch to v3.18

Thank you Dimitri for testing this.

Signed-off-by: John Crispin <blogic@openwrt.org>

SVN-Revision: 44430

target/linux/ar7/Makefile

@@ -13,7 +13,7 @@ FEATURES:=squashfs atm low_mem
 MAINTAINER:=Florian Fainelli <florian@openwrt.org>
 SUBTARGETS:=generic ac49x
 
-KERNEL_PATCHVER:=3.14
+KERNEL_PATCHVER:=3.18
 
 include $(INCLUDE_DIR)/target.mk