[PATCH 0/2] serial: fsl_lpuart: add eDMA support

[Yuan Yao]

Changed in v2:
- Add eDMA support for lpuart receive.
- Use dma_map_single in a right way.
- Use dma_mapping_error test dma_map_single.
- Change some names of variable.
- Fix some bugs.

Added in v1:
- Add device tree bindings for lupart eDMA support.
- Add eDMA support for lpuart send.