RDMA/cxgb3: Support the new memory registration API

Support the new memory registration API by allocating a
private page list array in iwch_mr and populate it when
iwch_map_mr_sg is invoked. Also, support IB_WR_REG_MR
by duplicating build_fastreg just take the needed information
from different places:
- page_size, iova, length (ib_mr)
- page array (iwch_mr)
- key, access flags (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>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/cxgb3/iwch_provider.h

@@ -77,6 +77,8 @@ struct iwch_mr {
 	struct iwch_dev *rhp;
 	u64 kva;
 	struct tpt_attributes attr;
+	u64 *pages;
+	u32 npages;
 };
 
 typedef struct iwch_mw iwch_mw_handle;