net/mlx5: Nack sync reset request when HotPlug is enabled

Current sync reset flow is not supported when PCIe bridge connected
directly to mlx5 device has HotPlug interrupt enabled and can be
triggered on link state change event. Return nack on reset request in
such case.

Fixes: 92501fa6

 ("net/mlx5: Ack on sync_reset_request only if PF can do reset_now")
Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>