[SCSI] mpt2sas : unique ioctl magic number

The current magic number is shared with mptsas driver. This to be unique to
fix issues with register_ioctls32_conversion in older kernels.  We are making
this change across all versions of the sas2.0 drivers.

Signed-off-by: Eric Moore <eric.moore@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>