arm64: dts: imx8qm-ss-dma: correct the dma channels of lpuart

arm64: dts: imx8qm-ss-dma: correct the dma channels of lpuart

The commit 616effc0272b5 ("arm64: dts: imx8: Fix lpuart DMA channel
order") swap uart rx and tx channel at common imx8-ss-dma.dtsi. But miss
update imx8qm-ss-dma.dtsi.

The commit 5a8e9b022e569 ("arm64: dts: imx8qm-ss-dma: Pass lpuart
dma-names") just simple add dma-names as binding doc requirement.

Correct lpuart0 - lpuart3 dma rx and tx channels, and use defines for
the FSL_EDMA_RX flag.

Fixes: 5a8e9b022e56 ("arm64: dts: imx8qm-ss-dma: Pass lpuart dma-names")
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>