common/mlx5: fix mkey attributes initialization

common/mlx5: fix mkey attributes initialization

The crypto driver added new fields to the mkey attributes struct:
crypto_en and set_remote_rw.

The entire mkey struct was not initialized, only specific fields in it,
which caused the new added fields not to be initialized resulting in a
mkey creation error.

This is fixed by initializing the entire mkey attributes struct to 0
which will prevent this issue from reoccurring if any fields are added
to the mkey struct in the future.

Fixes: 0111a74e13dd ("common/mlx5: adjust DevX mkey fields for crypto")
Signed-off-by: Shiri Kuzin <shirik@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>