libata: implement and use sata_std_hardreset()

Implement sata_std_hardreset(), which simply wraps around
sata_link_hardreset().  sata_std_hardreset() becomes new standard
hardreset method for sata_port_ops and sata_sff_hardreset() moves from
ata_base_port_ops to ata_sff_port_ops, which is where it really
belongs.

ata_is_builtin_hardreset() is added so that both
ata_std_error_handler() and ata_sff_error_handler() skip both builtin
hardresets if SCR isn't accessible.

piix_sidpr_hardreset() in ata_piix.c is identical to
sata_std_hardreset() in functionality and got replaced with the
standard function.

Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 08af43e..87f54a1 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -38,6 +38,15 @@
 	void			(*done)(struct scsi_cmnd *);
 };
 
+static inline int ata_is_builtin_hardreset(ata_reset_fn_t reset)
+{
+	if (reset == sata_std_hardreset)
+		return 1;
+	if (reset == sata_sff_hardreset)
+		return 1;
+	return 0;
+}
+
 /* libata-core.c */
 enum {
 	/* flags for ata_dev_read_id() */