igb: disable virtualization features on 82580

[ Upstream commit fa09bc40b21a33937872c4c4cf0f266ec9fa4869 ]

Disable virtualization features on 82580 just as on i210/i211.
This avoids that virt functions are acidentally called on 82850.

Fixes: 55cac248 ("igb: Add full support for 82580 devices")
Signed-off-by: Corinna Vinschen <vinschen@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>