With the previous ops standardization, pdc_adma now can inherit
ata_sff_port_ops instead of ata_base_port_ops.  Make the change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Mark Lord <liml@rtr.ca>
Signed-off-by: NJeff Garzik <jeff@garzik.org>