IB/{qib, hfi1, rdmavt}: Correct ibv_devinfo max_mr value

The command 'ibv_devinfo -v' reports 0 for max_mr.

Fix by assigning the query values after the mr lkey_table has been built
rather than early on in the driver.

Fixes: 7b1e2099

 ("IB/rdmavt: Move memory registration into rdmavt")
Reviewed-by: Josh Collier <josh.d.collier@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>