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>

drivers/infiniband/hw/amso1100/c2_rnic.c

@@ -454,7 +454,7 @@ int __devinit c2_rnic_init(struct c2_dev *c2dev)
 	    (IB_DEVICE_RESIZE_MAX_WR |
 	     IB_DEVICE_CURR_QP_STATE_MOD |
 	     IB_DEVICE_SYS_IMAGE_GUID |
-	     IB_DEVICE_ZERO_STAG |
+	     IB_DEVICE_LOCAL_DMA_LKEY |
 	     IB_DEVICE_MEM_WINDOW);
 
 	/* Allocate the qptr_array */