forked from Mirrors/opensbi

Add support for the UART provided by the LiteX SoC framework (https://github.com/enjoy-digital/litex), based on its FDT info (described in the Linux tree at Documentation/devicetree/bindings/serial/litex,liteuart.yaml). Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> Reviewed-by: Xiang W <wxjstz@126.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>