dma: ti: k3-udma: Introduce DMA support for the am62ax

In preparation for enabling ethernet for the am62ax family of SoCs,
introduce the initial DMA channel settings for the am62ax

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
[bb@ti.com: expanded on commit message]
Signed-off-by: Bryan Brattlof <bb@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>