libata: factor out ata_pci_activate_sff_host() from ata_pci_one()

Factor out ata_pci_activate_sff_host() from ata_pci_one().  This does
about the same thing as ata_host_activate() but needs to be separate
because SFF controllers use different and multiple IRQs in legacy
mode.

This will be used to make SFF LLD initialization more flexible.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 8c82193..ce803d1 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -7629,6 +7629,7 @@
 EXPORT_SYMBOL_GPL(ata_pci_init_sff_host);
 EXPORT_SYMBOL_GPL(ata_pci_init_bmdma);
 EXPORT_SYMBOL_GPL(ata_pci_prepare_sff_host);
+EXPORT_SYMBOL_GPL(ata_pci_activate_sff_host);
 EXPORT_SYMBOL_GPL(ata_pci_init_one);
 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
 #ifdef CONFIG_PM