* ARM AMBA Primecell PL011 serial UART

Required properties:
- compatible: must be "arm,primecell", "arm,pl011"
- reg: exactly one register range with length 0x1000
- interrupts: exactly one interrupt specifier

Optional properties:
- pinctrl: When present, must have one state named "sleep"
	   and one state named "default"
- clocks:  When present, must refer to exactly one clock named
	   "apb_pclk"
- dmas:	   When present, may have one or two dma channels.
	   The first one must be named "rx", the second one
	   must be named "tx".

See also bindings/arm/primecell.txt