* ARM SBSA defined generic UARTThis UART uses a subset of the PL011 registers and consequently livesin the PL011 driver. It's baudrate and other communication parameterscannot be adjusted at runtime, so it lacks a clock specifier here.Required properties:- compatible: must be "arm,sbsa-uart"- reg: exactly one register range- interrupts: exactly one interrupt specifier- current-speed: the (fixed) baud rate set by the firmware