ar71xx: update to linux 4.4

Signed-off-by: Felix Fietkau <[email protected]>

target/linux/ar71xx/Makefile

@@ -13,7 +13,7 @@ FEATURES:=mips16
 CPU_TYPE=34kc
 SUBTARGETS:=generic nand mikrotik
 
-KERNEL_PATCHVER:=4.1
+KERNEL_PATCHVER:=4.4
 
 include $(INCLUDE_DIR)/target.mk