Various libata documentation updates.

This is a merger of libata docs + cleanups from
Martin Waitz <tali@admingilde.org> and me.

From: Randy Dunlap <rdunlap@xenotime.net>
From: Martin Waitz <tali@admingilde.org>

Fix libata kernel-doc comments to match code.
Add some function parameters to kernel-doc.
Fix some typos/spellos.
Put comments in <= 80 columns.
Make one DPRINTK string unique.
Fix sparse cast warnings.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/scsi/ata_piix.c b/drivers/scsi/ata_piix.c
index 2d984b0..49cc420 100644
--- a/drivers/scsi/ata_piix.c
+++ b/drivers/scsi/ata_piix.c
@@ -630,6 +630,7 @@
 
 /**
  *	piix_check_450nx_errata	-	Check for problem 450NX setup
+ *	@ata_dev: the PCI device to check
  *	
  *	Check for the present of 450NX errata #19 and errata #25. If
  *	they are found return an error code so we can turn off DMA