* Thead light family IOPMP

Light family includes support SoC level IOPMP to limit master
access permission. It supports multiple valid iopmp regions configuration,
iopmp bypass, and only set default iopmp region.

Required Properties:
  - compatible: should be one of the following.
      * thead,light-iopmp - for light iopmp.

Example:

#include <include/dt-bindings/soc/thead,light-iopmp.h>

iopmp {
	compatible = "thead,light-iopmp";

	/* config#1: multiple valid regions */
	iopmp_emmc: IOPMP_EMMC {
		regions = <0x0 0x100000>,
			  <0x100000 0x200000>;
		attr = <0xFFFFFFFF>;
		dummy_slave= <0x800000>;
	};

	/* config#2: iopmp bypass */
	iopmp_sdio0: IOPMP_SDIO0 {
		bypass_en;
	};

	/* config#3: iopmp default region set */
	iopmp_sdio1: IOPMP_SDIO1 {
		attr = <0xFFFFFFFF>;
		is_default_region;
	};

	...
};
