[PATCH] libata: implement standard reset component operations and ->probe_reset

Implement SRST, COMRESET and standard postreset component operations
for ata_drive_probe_reset(), and use these three functions to
implement ata_std_probe_reset.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>