ata: ahci_platform: fix owner module reference mismatch for scsi host

The owner module reference of the ahci platform's scsi_host is
initialized to libahci_platform's one, because these drivers use a
scsi_host_template defined in libahci_platform.  So these drivers can
be unloaded even if the scsi device is being accessed.

This fixes it by pushing the scsi_host_template from libahci_platform
to all leaf drivers.  The scsi_host_template is passed through a new
argument of ahci_platform_init_host().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: linux-ide@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 2d18241..11beb419 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1338,6 +1338,12 @@
 extern const struct ata_port_operations sata_port_ops;
 extern struct device_attribute *ata_common_sdev_attrs[];
 
+/*
+ * All sht initializers (BASE, PIO, BMDMA, NCQ) must be instantiated
+ * by the edge drivers.  Because the 'module' field of sht must be the
+ * edge driver's module reference, otherwise the driver can be unloaded
+ * even if the scsi_device is being accessed.
+ */
 #define ATA_BASE_SHT(drv_name)					\
 	.module			= THIS_MODULE,			\
 	.name			= drv_name,			\