libata: make ata_pci_init_one() not use ops->irq_handler and pi->sht

ata_pci_init_one() is the only function which uses ops->irq_handler
and pi->sht.  Other initialization functions take the same information
as arguments.  This causes confusion and duplicate unused entries in
structures.

Make ata_pci_init_one() take sht as an argument and use ata_interrupt
implicitly.  All current users use ata_interrupt and if different irq
handler is necessary open coding ata_pci_init_one() using
ata_prepare_sff_host() and ata_activate_sff_host can be done under ten
lines including error handling and driver which requires custom
interrupt handler is likely to require custom initialization anyway.

As ata_pci_init_one() was the last user of ops->irq_handler, this
patch also kills the field.

Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/drivers/ata/pata_hpt3x2n.c b/drivers/ata/pata_hpt3x2n.c
index b77b127..2c178c3 100644
--- a/drivers/ata/pata_hpt3x2n.c
+++ b/drivers/ata/pata_hpt3x2n.c
@@ -452,7 +452,6 @@
 {
 	/* HPT372N and friends - UDMA133 */
 	static const struct ata_port_info info = {
-		.sht = &hpt3x2n_sht,
 		.flags = ATA_FLAG_SLAVE_POSS,
 		.pio_mask = 0x1f,
 		.mwdma_mask = 0x07,
@@ -568,7 +567,7 @@
 	}
 
 	/* Now kick off ATA set up */
-	return ata_pci_init_one(dev, ppi);
+	return ata_pci_init_one(dev, ppi, &hpt3x2n_sht);
 }
 
 static const struct pci_device_id hpt3x2n[] = {