net/mlx5: Use event mask based on device capabilities

Use the reported device capabilities for the supported user events (i.e.
affiliated and un-affiliated) to set the EQ mask.

As the event mask can be up to 256 defined by 4 entries of u64 change
the applicable code to work accordingly.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>