netvsc: Add #include's for csum_* function declarations

Add direct #include statements for declarations of csum_tcpudp_magic()
and csum_ipv6_magic().  While the needed #include's are picked up
indirectly for the x86 architecture, they aren't on other
architectures, resulting in compile errors.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/hyperv/netvsc_drv.c

@@ -37,6 +37,8 @@
 #include <net/route.h>
 #include <net/sock.h>
 #include <net/pkt_sched.h>
+#include <net/checksum.h>
+#include <net/ip6_checksum.h>
 
 #include "hyperv_net.h"