bcm53xx: switch to kernel 4.4

Initially 4.4 didn't work on bcm53xx because network was breaking few
seconds after setting interfaces. It's fixed since r48059 (switching
from 4.4-rc5 to 4.4-rc7).

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

SVN-Revision: 48510

target/linux/bcm53xx/Makefile

@@ -13,7 +13,7 @@ FEATURES:=squashfs nand usb pci pcie gpio
 MAINTAINER:=Hauke Mehrtens <hauke@hauke-m.de>
 CPU_TYPE:=cortex-a9
 
-KERNEL_PATCHVER:=4.1
+KERNEL_PATCHVER:=4.4
 
 include $(INCLUDE_DIR)/target.mk