drivers: dma_mcux_edma: Support EDMAv3 without dmamux

Support EDMAv3 platform that do not have dmamux or always on capability.
Therefore, memory to memory transfer is limited in this environment.

Signed-off-by: Declan Snyder <declan.snyder@nxp.com>
Co-authored-by: Emilio Benavente <emilio.benavente@nxp.com>