generic: add linux 4.1 support

Boot tested: http://pastebin.com/L6aAb9xj

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
[jogo:
  update to 4.1 final
  add patches added since submission
  delete patches applied in later rcs
  restore commit messages in 220-gc-sections and 304-mips_disable_fpu
  fix 050-backport_netfilter_rtcache to match new API
  update inlined dma ops with upstream changes
  add missing config symbols
  enabled CONFIG_MULTIUSER
  update kmod defintions for 4.1
]
Signed-off-by: Jonas Gorski <jogo@openwrt.org>

SVN-Revision: 46112

target/linux/generic/patches-4.1/616-net_optimize_xfrm_calls.patch

@@ -0,0 +1,12 @@
+--- a/net/netfilter/nf_nat_core.c
++++ b/net/netfilter/nf_nat_core.c
+@@ -90,6 +90,9 @@ int nf_xfrm_me_harder(struct sk_buff *sk
+ 	struct dst_entry *dst;
+ 	int err;
+ 
++	if (skb->dev && !dev_net(skb->dev)->xfrm.policy_count[XFRM_POLICY_OUT])
++		return 0;
++
+ 	err = xfrm_decode_session(skb, &fl, family);
+ 	if (err < 0)
+ 		return err;