[PATCH -next] libata.h: add stub for ata_sas_port_resume

[Randy Dunlap <rdunlap@infradead.org>]

From: Randy Dunlap <rdunlap@infradead.org>

Fix build error when CONFIG_PM is not enabled by adding a stub
function in <linux/libata.h>.

drivers/scsi/libsas/sas_ata.c: In function 'sas_resume_sata':
drivers/scsi/libsas/sas_ata.c:756:3: error: implicit declaration of function 'ata_sas_port_resume' [-Werror=implicit-function-declaration]

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Jim Davis <jim.epost@gmail.com>
---
 include/linux/libata.h |    3 +++
 1 file changed, 3 insertions(+)

--- linux-next-20140319.orig/include/linux/libata.h
+++ linux-next-20140319/include/linux/libata.h
@@ -1148,6 +1148,9 @@ static inline void ata_sas_port_suspend(
 static inline void ata_sas_port_async_resume(struct ata_port *ap)
 {
 }
+static inline void ata_sas_port_resume(struct ata_port *ap)
+{
+}
 #endif
 extern int ata_ratelimit(void);
 extern void ata_msleep(struct ata_port *ap, unsigned int msecs);