[SCSI] mptfusion: Better handling of DEAD IOC PCI-E Link down error condition

Find Non-Operation IOC and remove it from OS: Detecting
dead(non-functional) ioc will be done reading doorbell register value
from fault reset thread, which has been called from work thread
context after each specific interval. If doorbell value is 0xFFFFFFFF,
it will be considered as IOC is non-operational and marked as dead
ioc.

Once Dead IOC has been detected, it will be removed at pci layer using
"pci_remove_bus_device" API.

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>