scsi: megaraid_sas: Move initialization of instance parameters inside newly...

scsi: megaraid_sas: Move initialization of instance parameters inside newly created function megasas_init_ctrl_params

Code refactoring, no functional change. Create new function to
initialize all the controller parameters during load time.

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>