Bnx2x: remove redundant D0 power state set

Pci_enable_device() will set device power state to D0,
so it's no need to do it again in bnx2x_init_dev().
Also remove redundant PM Cap find code, because pci core
has been saved the pci device pm cap value.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>