RDMA/core: Remove protection from wrong in-kernel API usage

The ib_create_named_qp() is kernel verb that is not used for user supplied
attributes. In such case, it is ULP responsibility to provide valid QP
attributes.

In-kernel API shouldn't check it, exactly like other functions that don't
check device capabilities.

Link: https://lore.kernel.org/r/b9b9e981d1af148b750750196e686199dbbf61f8.1628014762.git.leonro@nvidia.com


Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>