libata: clean up dummy port_ops

Now that SFF assumptions are removed from core layer, dummy port_ops
can be slimmed down.  Chop it down.
Signed-off-by: Tejun Heo <htejun@gmail.com>

drivers/ata/libata-core.c

@@ -6159,32 +6159,20 @@ u32 ata_wait_register(void __iomem *reg, u32 mask, u32 val,
 /*
  * Dummy port_ops
  */
-static void ata_dummy_noret(struct ata_port *ap)	{ }
-static int ata_dummy_ret0(struct ata_port *ap)		{ return 0; }
-static void ata_dummy_qc_noret(struct ata_queued_cmd *qc) { }
-
-static u8 ata_dummy_check_status(struct ata_port *ap)
+static unsigned int ata_dummy_qc_issue(struct ata_queued_cmd *qc)
 {
-	return ATA_DRDY;
+	return AC_ERR_SYSTEM;
 }
 
-static unsigned int ata_dummy_qc_issue(struct ata_queued_cmd *qc)
+static void ata_dummy_error_handler(struct ata_port *ap)
 {
-	return AC_ERR_SYSTEM;
+	/* truly dummy */
 }
 
 struct ata_port_operations ata_dummy_port_ops = {
-	.sff_check_status	= ata_dummy_check_status,
-	.sff_check_altstatus	= ata_dummy_check_status,
 	.qc_prep		= ata_noop_qc_prep,
 	.qc_issue		= ata_dummy_qc_issue,
-	.freeze			= ata_dummy_noret,
-	.thaw			= ata_dummy_noret,
-	.error_handler		= ata_dummy_noret,
-	.post_internal_cmd	= ata_dummy_qc_noret,
-	.sff_irq_clear		= ata_dummy_noret,
-	.port_start		= ata_dummy_ret0,
-	.port_stop		= ata_dummy_noret,
+	.error_handler		= ata_dummy_error_handler,
 };
 
 const struct ata_port_info ata_dummy_port_info = {