* CA8210 IEEE 802.15.4 *

Required properties:
	- compatible:           Should be "cascoda,ca8210"
	- reg:                  Controlling chip select
	- spi-max-frequency:    Maximum clock speed, should be *less than*
	                        4000000
	- spi-cpol:             Invert clock polarity
	- reset-gpio:           GPIO attached to reset
	- irq-gpio:             GPIO attached to IRQ
Optional properties:
	- extclock-enable:      Include for the ca8210 to route its 16MHz clock
	                        to an output
	- extclock-freq:        Frequency in Hz of the external clock
	- extclock-gpio:        GPIO of the ca8210 to output the clock on

Example:
	ca8210@0 {
		compatible = "cascoda,ca8210";
		reg = <0>;
		spi-max-frequency = <3000000>;
		spi-cpol;
		reset-gpio = <&gpio1 1 GPIO_ACTIVE_HIGH>;
		irq-gpio = <&gpio1 2 GPIO_ACTIVE_HIGH>;
		extclock-enable;
		extclock-freq = 16000000;
		extclock-gpio = 2;
	};

* CA8210 IEEE 802.15.4 *

Required properties:
	- compatible:           Should be "cascoda,ca8210"
	- reg:                  Controlling chip select
	- spi-max-frequency:    Maximum clock speed, should be *less than*
	                        4000000
	- spi-cpol:             Requires inverted clock polarity (mode 2)
	- reset-gpio:           GPIO attached to reset
	- irq-gpio:             GPIO attached to IRQ
Optional properties:
	- extclock-enable:      Include for the ca8210 to route its 16MHz clock
	                        to an output
	- extclock-freq:        Frequency in Hz of the external clock
	- extclock-gpio:        GPIO of the ca8210 to output the clock on

Example:
	ca8210@0 {
		compatible = "cascoda,ca8210";
		reg = <0>;
		spi-max-frequency = <3000000>;
		spi-cpol;
		reset-gpio = <&gpio1 1 GPIO_ACTIVE_HIGH>;
		irq-gpio = <&gpio1 2 GPIO_ACTIVE_HIGH>;
		extclock-enable;
		extclock-freq = 16000000;
		extclock-gpio = 2;
	};

Clarify spi-cpol setting in device tree
Clarify spi-cpol setting in device tree

Make it clear in the device tree documentation that the spi-cpol
property is always necessary for the hardware to function.
