dmaengine: omap-dma: port_window support correction for both direction

When the port_window support was verified it was done on setup where only
the MEM_TO_DEV direction was enabled. This got un-noticed and thus only
this direction worked.

Now that I have managed to get a setup to verify both direction it turned
out that the setup was incorrect:
omap_desc members are settings for the slave port while the omap_sg members
apply to the memory side of the sDMA setup.

Fixes: 527a2759 ("dmaengine: omap-dma: Fix the port_window support")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: dmaengine@vger.kernel.org
Cc: dan.j.williams@intel.com
Cc: vinod.koul@intel.com
Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>