megaraid_sas: Update device queue depth based on interface type

This patch will update device Queue depth based on interface type(SAS,
SATA..) for sysPDs.  For Virtual disks(VDs), there will be no change in
queue depth (will remain 256).  To fetch interface type (SAS or SATA or
FC..) of syspD, driver will send DCMD MR_DCMD_PD_GET_INFO.

Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>