RDMA/core: Add local DMA L_Key support

- Change the IB_DEVICE_ZERO_STAG flag to the transport-neutral name
  IB_DEVICE_LOCAL_DMA_LKEY, which is used by iWARP RNICs to indicate 0
  STag support and IB HCAs to indicate reserved L_Key support.

- Add a u32 local_dma_lkey member to struct ib_device.  Drivers fill
  this in with the appropriate local DMA L_Key (if they support it).

- Fix up the drivers using this flag.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 07b41e0..90b529f 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -91,7 +91,7 @@
 	IB_DEVICE_RC_RNR_NAK_GEN	= (1<<12),
 	IB_DEVICE_SRQ_RESIZE		= (1<<13),
 	IB_DEVICE_N_NOTIFY_CQ		= (1<<14),
-	IB_DEVICE_ZERO_STAG		= (1<<15),
+	IB_DEVICE_LOCAL_DMA_LKEY	= (1<<15),
 	IB_DEVICE_RESERVED		= (1<<16), /* old SEND_W_INV */
 	IB_DEVICE_MEM_WINDOW		= (1<<17),
 	/*
@@ -1149,6 +1149,7 @@
 
 	char			     node_desc[64];
 	__be64			     node_guid;
+	u32			     local_dma_lkey;
 	u8                           node_type;
 	u8                           phys_port_cnt;
 };