pci_disable_device() is called in _suspend but there's no corresponding
pci_enable_device() in _resume.
This causes "disabling already-disabled device" warning on 2nd suspend.

Add pci_enable_device() call to _resume to fix this problem.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: David S. Miller <davem@davemloft.net>