TI-NSPIRE Clocks

Required properties:
- compatible: Valid compatible properties include:
	"lsi,nspire-cx-ahb-divider" for the AHB divider in the CX model
	"lsi,nspire-classic-ahb-divider" for the AHB divider in the older model
	"lsi,nspire-cx-clock" for the base clock in the CX model
	"lsi,nspire-classic-clock" for the base clock in the older model

- reg: Physical base address of the controller and length of memory mapped
	region.

Optional:
- clocks: For the "nspire-*-ahb-divider" compatible clocks, this is the parent
	clock where it divides the rate from.

Example:

ahb_clk {
	#clock-cells = <0>;
	compatible = "lsi,nspire-cx-clock";
	reg = <0x900B0000 0x4>;
	clocks = <&base_clk>;
};