ssb/trivial: replace numeric with standard PM state macros

Use standard PM state macros PCI_Dx instead of numeric 0/1/2..

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>