Documentation: move SCSI parameters to their own text file

Move SCSI parameters from kernel-parameters.txt to their own text file.

This continues a trend of moving non-core parameters out of
kernel-parameters.txt.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>