sky2: power management/MSI workaround

MSI doesn't work properly on resume on many platforms because the
BIOS goes and changes it back to INTx mode after the sky2 driver has
restored in resume.

It is really a bug in the base power management resume code, and
this workaround is temporary until the change to PM code works it's way
through the release process.  The PM fix is non-trivial since it needs
to change when non-boot CPU's are enabled.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>