[SCSI] raid_class.c - adding RAID10 and RAID10 defines

Adding defines for RAID10 and RAID50 levels, in preparation
of adding RAID Transport support in the mpt fusion drivers.
(BTW: IME is RAID10, and IM is RAID1).

Signed-off-by: Eric Moore <Eric.Moore@lsil.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>