Early domain core driver.

Early domain in bootloader run multimedia services like display,
camera, audio by reserving cpu(s) and some memory in parallel with
kernel.

These services may need to stop when they decide. Early domain
driver in kernel communicates with early services through a shared
memory block. This block is reserved during kernel boot.

Early services running in bootloader update their status in the
shared memory block. Multimedia drivers in kernel can make use of
apis provided by early domain core driver to get the status of early
services and free reserved memory resource to system
when the early services end.

Required properties
- compatible : 	should be "qcom,early_domain"
- status     : 	should be "disabled" by default.
		status should be made "ok" only
		if earlydomain is active by
		bootloaders.

Example:
	early_domain: early_domain  {
			compatible = "qcom,early_domain";
			status = "disabled";
	};

