dmaengine: ti-dma-crossbar: Add support for crossbar on AM33xx/AM43xx

The DMA event crossbar on AM33xx/AM43xx is different from the one found in
DRA7x family.
Instead of a single event crossbar it has 64 identical mux attached to each
eDMA event line. When the 0 event mux is selected, the default mapped event
is going to be routed to the corresponding eDMA event line. If different
mux is selected, then the selected event is going to be routed to the given
eDMA event.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>