libata: normalize port_info, port_operations and sht tables

Over the time, port info, ops and sht structures developed quite a bit
of inconsistencies.  This patch updates drivers.

* Enable/disable_pm callbacks added to all ahci ops tables.

* Every driver for SFF controllers now uses ata_sff_port_start()
  instead of ata_port_start() unless the driver has custom
  implementation.

* Every driver for SFF controllers now uses ata_pci_default_filter()
  unless the driver has custom implementation.

* Removed an odd port_info->sht initialization from ata_piix.c.
  Likely a merge byproduct.

* A port which has ATA_FLAG_SATA set doesn't need to set cable_detect
  to ata_cable_sata().  Remove it from via and mv port ops.

* Some drivers had unnecessary .max_sectors initialization which is
  ignored and was missing .slave_destroy callback.  Fixed.

* Removed unnecessary sht initializations port_info's.

* Removed onsolete scsi device suspend/resume callbacks from
  pata_bf54x.

* No reason to set ata_pci_default_filter() and bmdma functions for
  PIO-only drivers.  Remove those callbacks and replace
  ata_bmdma_irq_clear with ata_noop_irq_clear.

* pata_platform sets port_start to ata_dummy_ret0.  port_start can
  just be set to NULL.

* sata_fsl supports NCQ but was missing qc_defer.  Fixed.

* pata_rb600_cf implements dummy port_start.  Removed.

Signed-off-by: Tejun Heo <htejun@gmail.com>

drivers/ata/pata_platform.c

@@ -46,8 +46,6 @@ static int pata_platform_set_mode(struct ata_link *link, struct ata_device **unu
 	return 0;
 }
 
-static int ata_dummy_ret0(struct ata_port *ap)	{ return 0; }
-
 static struct scsi_host_template pata_platform_sht = {
 	.module			= THIS_MODULE,
 	.name			= DRV_NAME,
@@ -88,8 +86,6 @@ static struct ata_port_operations pata_platform_port_ops = {
 
 	.irq_clear		= ata_noop_irq_clear,
 	.irq_on			= ata_irq_on,
-
-	.port_start		= ata_dummy_ret0,
 };
 
 static void pata_platform_setup_port(struct ata_ioports *ioaddr,