[PATCH] pci: only call pci_restore_bars at boot

Certain (SGI?) ia64 boxes object to having their PCI BARs
restored unless absolutely necessary. This patch restricts calling
pci_restore_bars from pci_set_power_state unless the current state
is PCI_UNKNOWN, the actual (i.e. physical) state of the device is
PCI_D3hot, and the device indicates that it will lose its configuration
when transitioning to PCI_D0.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>