kernel: add linux 4.4 support

Based on 4.4-rc3. Runtime tested on MIPS.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

SVN-Revision: 47701

target/linux/generic/patches-4.4/653-disable_netlink_trim.patch

@@ -0,0 +1,30 @@
+--- a/net/netlink/af_netlink.c
++++ b/net/netlink/af_netlink.c
+@@ -1795,27 +1795,7 @@ void netlink_detachskb(struct sock *sk,
+ 
+ static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
+ {
+-	int delta;
+-
+ 	WARN_ON(skb->sk != NULL);
+-	if (netlink_skb_is_mmaped(skb))
+-		return skb;
+-
+-	delta = skb->end - skb->tail;
+-	if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize)
+-		return skb;
+-
+-	if (skb_shared(skb)) {
+-		struct sk_buff *nskb = skb_clone(skb, allocation);
+-		if (!nskb)
+-			return skb;
+-		consume_skb(skb);
+-		skb = nskb;
+-	}
+-
+-	if (!pskb_expand_head(skb, 0, -delta, allocation))
+-		skb->truesize -= delta;
+-
+ 	return skb;
+ }
+