[libata] mark certain hardware (or drivers) with a no-atapi flag

Some hardware does not support the PACKET command at all.
Other hardware supports ATAPI, but the driver does something nasty such
as calling BUG() when an ATAPI command is issued.

For these such cases, we mark them with a new flag, ATA_FLAG_NO_ATAPI.

Initial version contributed by Ben Collins.

include/linux/libata.h

@@ -122,6 +122,7 @@ enum {
 	ATA_FLAG_NOINTR		= (1 << 9), /* FIXME: Remove this once
 					     * proper HSM is in place. */
 	ATA_FLAG_DEBUGMSG	= (1 << 10),
+	ATA_FLAG_NO_ATAPI	= (1 << 11), /* No ATAPI support */
 
 	ATA_QCFLAG_ACTIVE	= (1 << 1), /* cmd not yet ack'd to scsi lyer */
 	ATA_QCFLAG_SG		= (1 << 3), /* have s/g table? */