* Asahi Kasei AKM89XX compass sensor

Required properties:
- compatible: should be one of the following.
  - "ak,ak8963"
  - "ak,ak8972"
  - "ak,ak8975"
- reg: the I2C address of AKM89XX
- config: the selection determines the device behavior.
  - "auto": auto detect connection to MPU
  - "mpu": connected to MPU
  - "host": connected to host
- orientation: the orientation matricies are 3x3 rotation matricies that are
  applied to the data to rotate from the mounting orientation to the platform
  orientation. The values must be one of 0, 1, or -1(0xff in byte array) and
  each row and column should have exactly 1 non-zero value.

Example:

akm8963@0d {
	compatible = "ak,ak8963";
	reg = <0x0d>;
	orientation = [00 01 00 ff 00 00 00 00 01];
	config = "mpu";
};
