net/mlx5: Add structure and defines for pci sync for fw update event

Add needed structure layouts and defines for pci sync for fw update
event. The downstream patches will include event handlers for this event
type.

Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>