arm64: ls104x: Enable eDMA snooping

This enables eDMA snooping on the LS1043A and LS1046A. This will allow
marking the I2C, LPUART, and SPI devices on these SoCs as DMA coherent.
Oddly, this bit is only documented for the LS1043A, and is marked as
"reserved" in the LS1046ARM. I have tested this patch on the LS1046A
and found that marking i2c0 as dma-coherent works without issue.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Acked-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>