dmaengine: shdmac: extend PM methods

In order to make it possible to restore from hibernation not only in Linux but
also in e.g. U-Boot, we have to use sh_dmae_{suspend|resume}() for the {freeze|
thaw|restore}() PM methods. It's handy to achieve this with SIMPLE_DEV_PM_OPS()
macro; since  that macro doesn't do anything when CONFIG_PM_SLEEP  is undefined,
we don't need to #define sh_dmae_{suspend|resume} NULL anymore but we'll have to
enclose sh_dmae_{suspend|resume}() into the new #ifdef...

Based on original patch by Mikhail Ulyanov <mikhail.ulyanov@cogentembedded.com>.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/sh/shdmac.c

@@ -600,7 +600,9 @@ static int sh_dmae_runtime_resume(struct device *dev)
 
 	return sh_dmae_rst(shdev);
 }
+#endif
 
+#ifdef CONFIG_PM_SLEEP
 static int sh_dmae_suspend(struct device *dev)
 {
 	return 0;
@@ -632,14 +634,10 @@ static int sh_dmae_resume(struct device *dev)
 
 	return 0;
 }
-#else
-#define sh_dmae_suspend NULL
-#define sh_dmae_resume NULL
 #endif
 
 static const struct dev_pm_ops sh_dmae_pm = {
-	.suspend		= sh_dmae_suspend,
-	.resume			= sh_dmae_resume,
+	SET_SYSTEM_SLEEP_PM_OPS(sh_dmae_suspend, sh_dmae_resume)
 	SET_RUNTIME_PM_OPS(sh_dmae_runtime_suspend, sh_dmae_runtime_resume,
 			   NULL)
 };