RDMA/mlx5: Fix AH static rate parsing

RDMA/mlx5: Fix AH static rate parsing

Previously static rate wasn't translated according to our PRM but simply
used the 4 lower bytes.

Correctly translate static rate value passed in AH creation attribute
according to our PRM expected values.

In addition change 800GB mapping to zero, which is the PRM
specified value.

Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: Patrisious Haddad <phaddad@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Link: https://patch.msgid.link/18ef4cc5396caf80728341eb74738cd777596f60.1739187089.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>