cns3xxx: switch to linux 4.9

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

target/linux/cns3xxx/Makefile

@@ -14,7 +14,7 @@ CPU_TYPE:=mpcore
 CPU_SUBTYPE:=vfp
 MAINTAINER:=Felix Fietkau <[email protected]>
 
-KERNEL_PATCHVER:=4.4
+KERNEL_PATCHVER:=4.9
 
 define Target/Description
 	Build images for Cavium Networks Econa CNS3xxx based boards,