Analog Devices ADF4350/ADF4351 device driver

Required properties:
	- compatible: Should be one of
		* "adi,adf4350": When using the ADF4350 device
		* "adi,adf4351": When using the ADF4351 device
	- reg: SPI chip select numbert for the device
	- spi-max-frequency: Max SPI frequency to use (< 20000000)
	- clocks: From common clock binding. Clock is phandle to clock for
		ADF435x Reference Clock (CLKIN).

Optional properties:
	- gpios:	 GPIO Lock detect - If set with a valid phandle and GPIO number,
			pll lock state is tested upon read.
	- adi,channel-spacing: Channel spacing in Hz (influences MODULUS).
	- adi,power-up-frequency:	If set in Hz the PLL tunes to
			the desired frequency on probe.
	- adi,reference-div-factor: If set the driver skips dynamic calculation
			and uses this default value instead.
	- adi,reference-doubler-enable: Enables reference doubler.
	- adi,reference-div2-enable: Enables reference divider.
	- adi,phase-detector-polarity-positive-enable: Enables positive phase
			detector polarity. Default = negative.
	- adi,lock-detect-precision-6ns-enable: Enables 6ns lock detect precision.
			Default = 10ns.
	- adi,lock-detect-function-integer-n-enable: Enables lock detect
			for integer-N mode. Default = factional-N mode.
	- adi,charge-pump-current: Charge pump current in mA.
			Default = 2500mA.
	- adi,muxout-select: On chip multiplexer output selection.
			Valid values for the multiplexer output are:
			0: Three-State Output (default)
			1: DVDD
			2: DGND
			3: R-Counter output
			4: N-Divider output
			5: Analog lock detect
			6: Digital lock detect
	- adi,low-spur-mode-enable: Enables low spur mode.
			Default = Low noise mode.
	- adi,cycle-slip-reduction-enable: Enables cycle slip reduction.
	- adi,charge-cancellation-enable: Enabled charge pump
			charge cancellation for integer-N modes.
	- adi,anti-backlash-3ns-enable: Enables 3ns antibacklash pulse width
			 for integer-N modes.
	- adi,band-select-clock-mode-high-enable: Enables faster band
			selection logic.
	- adi,12bit-clk-divider: Clock divider value used when
			adi,12bit-clkdiv-mode != 0
	- adi,clk-divider-mode:
			Valid values for the clkdiv mode are:
			0: Clock divider off (default)
			1: Fast lock enable
			2: Phase resync enable
	- adi,aux-output-enable: Enables auxiliary RF output.
	- adi,aux-output-fundamental-enable: Selects fundamental VCO output on
			the auxiliary RF output. Default = Output of RF dividers.
	- adi,mute-till-lock-enable: Enables Mute-Till-Lock-Detect function.
	- adi,output-power: Output power selection.
			Valid values for the power mode are:
			0: -4dBm (default)
			1: -1dBm
			2: +2dBm
			3: +5dBm
	- adi,aux-output-power: Auxiliary output power selection.
			Valid values for the power mode are:
			0: -4dBm (default)
			1: -1dBm
			2: +2dBm
			3: +5dBm


Example:
		lo_pll0_rx_adf4351: adf4351-rx-lpc@4 {
			compatible = "adi,adf4351";
			reg = <4>;
			spi-max-frequency = <10000000>;
			clocks = <&clk0_ad9523 9>;
			clock-names = "clkin";
			adi,channel-spacing = <10000>;
			adi,power-up-frequency = <2400000000>;
			adi,phase-detector-polarity-positive-enable;
			adi,charge-pump-current = <2500>;
			adi,output-power = <3>;
			adi,mute-till-lock-enable;
		};
