Revert "scsi: megaraid_sas: Enable or Disable Fast path based on the PCI Threshold Bandwidth"

This reverts commit "3e5eadb1" ("scsi: megaraid_sas: Enable or
Disable Fast path based on the PCI Threshold Bandwidth")

This patch was aimed to increase performance of R1 Write operation for
large IO size.  Since this method used timer approach, it turn on/off
fast path did not work as expected.  Patch 0013 describes new algorithm
and performance number.

Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>