RDMA/hns: Modify uar allocation algorithm to avoid bitmap exhaust

RDMA/hns: Modify uar allocation algorithm to avoid bitmap exhaust

BugLink: https://bugs.launchpad.net/bugs/1770974
This patch modified uar allocation algorithm in hns_roce_uar_alloc
function to avoid bitmap exhaust.

Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
(cherry picked from commit 5b6eb54f586ba0a6385f1523bce4c96cbdb79afd linux-next)
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>