RDMA/mlx5: Round max_rd_atomic/max_dest_rd_atomic up instead of down

RDMA/mlx5: Round max_rd_atomic/max_dest_rd_atomic up instead of down

After the cited commit below max_dest_rd_atomic and max_rd_atomic values
are being rounded down to the next power of 2. As opposed to the old
behavior and mlx4 driver where they used to be rounded up instead.

In order to stay consistent with older code and other drivers, revert to
using fls round function which rounds up to the next power of 2.

Fixes: f18e26af6aba ("RDMA/mlx5: Convert modify QP to use MLX5_SET macros")
Link: https://patch.msgid.link/r/d85515d6ef21a2fa8ef4c8293dce9b58df8a6297.1728550179.git.leon@kernel.org
Signed-off-by: Patrisious Haddad <phaddad@nvidia.com>
Reviewed-by: Maher Sanalla <msanalla@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>