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/include/linux/libata.h b/include/linux/libata.h
index bc4ee21..2fbd22b 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1004,8 +1004,9 @@
 extern void ata_host_resume(struct ata_host *host);
 #endif
 extern int ata_ratelimit(void);
-extern u32 ata_wait_register(void __iomem *reg, u32 mask, u32 val,
-			     unsigned long interval, unsigned long timeout);
+extern void ata_msleep(struct ata_port *ap, unsigned int msecs);
+extern u32 ata_wait_register(struct ata_port *ap, void __iomem *reg, u32 mask,
+			u32 val, unsigned long interval, unsigned long timeout);
 extern int atapi_cmd_type(u8 opcode);
 extern void ata_tf_to_fis(const struct ata_taskfile *tf,
 			  u8 pmp, int is_cmd, u8 *fis);