dma: shdma: fix runtime PM: clear channel buffers on reset

On platforms, supporting power domains, if the domain, containing a DMAC
instance is powered down, the driver fails to resume correctly. On those
platforms DMAC channels have an additional CHCLR register for clearing
channel buffers. Using this register during runtime resume fixes the
problem.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
diff --git a/include/linux/sh_dma.h b/include/linux/sh_dma.h
index 62ef693..8cd7fe5 100644
--- a/include/linux/sh_dma.h
+++ b/include/linux/sh_dma.h
@@ -48,6 +48,7 @@
 	unsigned int	offset;
 	unsigned int	dmars;
 	unsigned int	dmars_bit;
+	unsigned int	chclr_offset;
 };
 
 struct sh_dmae_pdata {
@@ -68,6 +69,7 @@
 	unsigned int dmaor_is_32bit:1;
 	unsigned int needs_tend_set:1;
 	unsigned int no_dmars:1;
+	unsigned int chclr_present:1;
 };
 
 /* DMA register */