IB/core: Guarantee that a local_dma_lkey is available

IB/core: Guarantee that a local_dma_lkey is available

Every single ULP requires a local_dma_lkey to do anything with
a QP, so let us ensure one exists for every PD created.

If the driver can supply a global local_dma_lkey then use that, otherwise
ask the driver to create a local use all physical memory MR associated
with the new PD.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Sagi Grimberg <sagig@dev.mellanox.co.il>
Acked-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Tested-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>