dmaengine: edma: Add dummy driver skeleton for edma3-tptc

The eDMA3 TPTC does not need any software configuration, but it is a
separate IP block in the SoC. In order the omap hwmod core to be able to
handle the TPTC resources correctly in regards of PM we need to have a
driver loaded for it.
This patch will add a dummy driver skeleton without probe or remove
callbacks provided.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reported-by: Olof Johansson <olof@lixom.net>
Tested-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>