dma: shdma: transfer based runtime PM

Currently the shdma dmaengine driver uses runtime PM to save power, when
no channel on the specific controller is requested by a user. This patch
switches the driver to count individual DMA transfers. That way the
controller can be powered down between transfers, even if some of its
channels are in use.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
(cherry picked from commit 7a1cd9ad87979744e1510782b25c38feb9602739)

Signed-off-by: Simon Horman <horms@verge.net.au>
2 files changed