RDMA/ocrdma: Cache recv DB until QP moved to RTR

1) In post recv, don't ring the DB doorbell if the QP is in RTR state.
   Cache the DB calls, until the QP is moved to RTS state.
2) Add max_rd_sge support to dev->attr.
3) Code cleanup in alloc_pd path.

Signed-off-by: Naresh Gottumukkala <bgottumukkala@emulex.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/ocrdma/ocrdma_sli.h

@@ -1306,7 +1306,7 @@ struct ocrdma_reg_nsmr_cont {
 	u32 last;
 
 	struct ocrdma_pa pbl[MAX_OCRDMA_NSMR_PBL];
-} __packed;
+};
 
 struct ocrdma_pbe {
 	u32 pa_hi;