cxgb4: Increased the value of MAX_IMM_TX_PKT_LEN from 128 to 256 bytes

This allows a significant latency drop for packets of sizes between 128 and 192
bytes
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/sge.c

@@ -144,7 +144,7 @@
  * Max Tx descriptor space we allow for an Ethernet packet to be inlined
  * into a WR.
  */
-#define MAX_IMM_TX_PKT_LEN 128
+#define MAX_IMM_TX_PKT_LEN 256
 
 /*
  * Max size of a WR sent through a control Tx queue.