usb: musb: tusb6010_omap: Convert to DMAengine API

With the port_window support in DMAengine and the sDMA driver we can
convert the driver to DMAengine.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>