ata: add ata port system PM callbacks

Change ata_host_request_pm to ata_port_request_pm which performs
port suspend/resume.

Add ata port type driver which implements port PM callbacks.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
3 files changed