`bootargs = "console=ttyS0,57600";` is already defined on all
ramips target SoCs' dtsi. We don't need to override it with the
same value.
Signed-off-by: Shiji Yang <yangshiji66@qq.com>
Link: https://github.com/openwrt/openwrt/pull/18303
Signed-off-by: Robert Marko <robimarko@gmail.com>