libata: add @ap to ata_wait_register() and introduce ata_msleep()

Add optional @ap argument to ata_wait_register() and replace msleep()
calls with ata_msleep() which take optional @ap in addition to the
duration.  These will be used to implement EH exclusion.

This patch doesn't cause any behavior difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/sata_inic162x.c b/drivers/ata/sata_inic162x.c
index a36149e..83a4447 100644
--- a/drivers/ata/sata_inic162x.c
+++ b/drivers/ata/sata_inic162x.c
@@ -614,7 +614,7 @@
 
 	writew(IDMA_CTL_RST_ATA, idma_ctl);
 	readw(idma_ctl);	/* flush */
-	msleep(1);
+	ata_msleep(ap, 1);
 	writew(0, idma_ctl);
 
 	rc = sata_link_resume(link, timing, deadline);