scsi: sd: Move DIF protection types to t10-pi.h

These should go together with the rest of the T10 protection information
defintions.

[mkp: s/T10_DIF/T10_PI/]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>