dmaengine: shdma: add runtime- and system-level power management

This patch extends and fixes runtime power management in the shdma
driver to support powering down the DMA controller and adds support
for system-level suspend and resume.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/drivers/dma/shdma.h b/drivers/dma/shdma.h
index 52e4fb1..3f9d3cd 100644
--- a/drivers/dma/shdma.h
+++ b/drivers/dma/shdma.h
@@ -37,6 +37,7 @@
 	int id;				/* Raw id of this channel */
 	u32 __iomem *base;
 	char dev_id[16];		/* unique name per DMAC of channel */
+	int pm_error;
 };
 
 struct sh_dmae_device {