[SCSI] libosd: Not implemented commands

Some commands declared in header are not yet implemented. Put them
as stubs in .c file, just so they take their place in the file

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Reviewed-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>