net: fix driver build errors due to missing net/ip6_checksum.h include

  2.6.27-git2 kernel build fails with allyesconfig on powerpc with 
build error 

<introduced by commit 01f2e4ea> 

CC    drivers/net/enic/enic_main.o
drivers/net/enic/enic_main.c: In function ‘enic_queue_wq_skb_tso’:
drivers/net/enic/enic_main.c:576: error: implicit declaration of function ‘csum_ipv6_magic’
make[3]: *** [drivers/net/enic/enic_main.o] Error 1

<introduced by commit c4e84bde>

drivers/net/qlge/qlge_main.c: In function ‘ql_tso’:
drivers/net/qlge/qlge_main.c:1862: error: implicit declaration of function ‘csum_ipv6_magic’
make[3]: *** [drivers/net/qlge/qlge_main.o] Error 1
  
<introduced by commit 95252236>

drivers/net/jme.c: In function ‘jme_tx_tso’:
drivers/net/jme.c:1784: error: implicit declaration of function ‘csum_ipv6_magic’
make[2]: *** [drivers/net/jme.o] Error 1
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Ron Mercer <ron.mercer@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/enic/enic_main.c

@@ -34,6 +34,7 @@
 #include <linux/ip.h>
 #include <linux/ipv6.h>
 #include <linux/tcp.h>
+#include <net/ip6_checksum.h>
 
 #include "cq_enet_desc.h"
 #include "vnic_dev.h"

drivers/net/jme.c

@@ -37,6 +37,7 @@
 #include <linux/tcp.h>
 #include <linux/udp.h>
 #include <linux/if_vlan.h>
+#include <net/ip6_checksum.h>
 #include "jme.h"
 
 static int force_pseudohp = -1;

drivers/net/qlge/qlge_main.c

@@ -39,6 +39,7 @@
 #include <linux/delay.h>
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
+#include <net/ip6_checksum.h>
 
 #include "qlge.h"