dt-bindings: dma: fsl-edma: allow 'power-domains' property

Allow 'power-domains' property because i.MX8DXL i.MX8QM and i.MX8QXP need
it. EDMA supports each power-domain for each dma channel. So minItems and
maxItems align 'dma-channels'.

Change fsl,imx93-edma3 example to fsl,imx8qm-edma to reflect this variants.

Fixed below DTB_CHECK warning:
  dma-controller@599f0000: Unevaluated properties are not allowed ('power-domains' was unexpected)

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20240417152457.361340-2-Frank.Li@nxp.com


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