via-velocity: Implement NAPI support

This patch adds NAPI support for VIA velocity. The new velocity_poll
function also pairs tx/rx handling twice which improves perforamance on
some workloads (e.g., netperf UDP_STREAM) significantly (that part is
from the VIA driver).

Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/via-velocity.h b/drivers/net/via-velocity.h
index 499da64..d37a303 100644
--- a/drivers/net/via-velocity.h
+++ b/drivers/net/via-velocity.h
@@ -32,6 +32,7 @@
 #define VELOCITY_VERSION       "1.14"
 
 #define VELOCITY_IO_SIZE	256
+#define VELOCITY_NAPI_WEIGHT	64
 
 #define PKT_BUF_SZ          1540
 
@@ -1562,6 +1563,8 @@
 	u32 ticks;
 
 	u8 rev_id;
+
+	struct napi_struct napi;
 };
 
 /**