ata: SWNCQ should be enabled by default

Signed-off-by: Zoltan Boszormenyi <zboszor@dunaweb.hu>
Cc: Robert Hancock <hancockr@shaw.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>