bnx2: use pdev->pm_cap instead of pci_find_capability(.., PCI_CAP_ID_PM)

bnx2: use pdev->pm_cap instead of pci_find_capability(.., PCI_CAP_ID_PM)

Pci core has been saved pm cap register offset by pdev->pm_cap in pci_pm_init()
in init path. So we can use pdev->pm_cap instead of using
pci_find_capability(pdev, PCI_CAP_ID_PM) for better performance and simplified code.

Signed-off-by: Yijing Wang <[email protected]>
Cc: Michael Chan <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: David S. Miller <[email protected]>