cciss: PCI power management reset for kexec

The kexec kernel resets the CCISS hardware in three steps:

1. Use PCI power management states to reset the controller in the
   kexec kernel.

2. Clear the MSI/MSI-X bits in PCI configuration space so that MSI
   initialization in the kexec kernel doesn't fail.

3. Use the CCISS "No-op" message to determine when the controller
   firmware has recovered from the PCI PM reset.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>