cxgb4: use the correct max size for firmware flash

The wrong max fw size was being used and causing false
"too big" errors running ethtool -f.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
index fb2fe65..bba6768 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
@@ -682,7 +682,7 @@
 	SF_RD_ID        = 0x9f,       /* read ID */
 	SF_ERASE_SECTOR = 0xd8,       /* erase sector */
 
-	FW_MAX_SIZE = 512 * 1024,
+	FW_MAX_SIZE = 16 * SF_SEC_SIZE,
 };
 
 /**