scsi: megaraid_sas: Do not limit queue_depth to 1k in non-RDPQ mode

Driver load fails if memory allocation for request frame pool fails due
to the higher queue_depth requirement. The driver now allows dynamically
reducing queue_depth if memory allocations fail rather than failing
load.  With this, there is no need to limit queue_depth to 1K.

Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>