IB/mlx4: Support the new memory registration API

Support the new memory registration API by allocating a
private page list array in mlx4_ib_mr and populate it when
mlx4_ib_map_mr_sg is invoked. Also, support IB_WR_REG_MR
by setting the exact WQE as IB_WR_FAST_REG_MR, just take the
needed information from different places:
- page_size, iova, length, access flags (ib_mr)
- page array (mlx4_ib_mr)
- key (ib_reg_wr)

The IB_WR_FAST_REG_MR handlers will be removed later when
all the ULPs will be converted.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx4/cq.c

@@ -819,6 +819,7 @@ repoll:
 			break;
 		case MLX4_OPCODE_FMR:
 			wc->opcode    = IB_WC_FAST_REG_MR;
+			/* TODO: wc->opcode    = IB_WC_REG_MR; */
 			break;
 		case MLX4_OPCODE_LOCAL_INVAL:
 			wc->opcode    = IB_WC_LOCAL_INV;