dmaengine: ti: k3-udma: Use common defines for TCHANRT/RCHANRT registers

The register offsets and functions are the same among TCHAN and RCHAN.
Use generic, common names for them.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Link: https://lore.kernel.org/r/20200707102352.28773-4-peter.ujfalusi@ti.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>