[SCSI] megaraid_sas: Add new megaraid SAS 2 controller support to the driver

Add the new megaraid sas 2 controller to the driver.  megaraid sas2 is
LSI next generation SAS products.  driver add the interface to support
this product.

Signed-off-by Bo Yang<bo.yang@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>