dmaengine: edma: Add probe callback to edma_tptc_driver

Due to changes in device and platform code drivers w/o probe will fail to
load. This means that the devices for eDMA TPTCs are goign to be without
driver and omap hwmod code will turn them off after the kernel finished
loading:
[    3.015900] platform 49800000.tptc: omap_device_late_idle: enabled but no driver.  Idling
[    3.024671] platform 49a00000.tptc: omap_device_late_idle: enabled but no driver.  Idling

This will prevent eDMA to work since the TPTCs are not enabled.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Fixes: 34635b1a ("dmaengine: edma: Add dummy driver skeleton for edma3-tptc")
Signed-off-by: Vinod Koul <vinod.koul@intel.com>