Documentation: Add device tree bindings for msm-id and board-id

* BOARD-ID

The qcom,board-id entry specifies the MSM platform and subtype revision.

It can optionally be an array of these to indicate multiple hardware that use

the same device tree.  It is expected that the bootloader will use this

information at boot-up to decide which device tree to use when given multiple

device trees, some of which may not be compatible with the actual hardware.  It

is the bootloader's responsibility to pass the correct device tree to the kernel.

Legacy format:

It is expected that the qcom,board-id entry be at the top level of the device

tree structure.  The format of the entry is:

   qcom,board-id = <platform_id, subtype_id> [, <p2, s2> ...]

where platform_id and subtype_id are the numeric values for the platform and

subtype of the current hardware.

The "subtype_id" cell is a 32-bit integer whose bit values are defined as follows:

    bits 31-20 = Reserved bits

    bits 19-16 = Boot Device Type.

		 MSM:

		     0: default (eMMC)

		     2: EMMC_SDC1

		     4: BOOT_UFS

		 MDM:

		     0: default (NAND)

		     3: EMMC_SDC1

    bits 15-8  = DDR Size. For devices with DDR Size as 512MB the value is 0x1, default value as 0x0

    bits 7-0   = Platform Subtype

In the event that a given device tree is applicable to all hardware versions

matching a given Platform Type / Subtype ID, the major/minior platform version

fields in the board_id property shall both be specified as 0xff.

Modern format:

The cell layout of the qcom,board-id property is as follows:

   qcom,board-id = <board_id, reserved>

where board_id is a 32-bit integer whose bit values are defined as follows:

    bits 31-24 = Platform Subtype ID

    bits 23-16 = Platform Version (Major)

    bits 15-8  = Platform Version (Minor)

    bits  7-0  = Platform Type ID

and the 'reserved' cell is a 32-bit integer whose bit values are defined as follows:

    bits 31-13 = Reserved Bits

    bits 12-11 = Panel Detection. 00 - limit to HD, 01 - limit to 720p,

		 10 - limit to qHD, 11 - limit to FWVGA

    bits 10-8  = DDR Size. For devices with DDR Size as 512MB the value is 0x1,

		 default value as 0x0

    bits 7-0   = Platform Subtype

In the event that a given device tree is applicable to all hardware versions

matching a given Platform Type / Subtype ID, the major/minior platform version

fields in the board_id property shall both be specified as 0xff.

Example:

   qcom,board-id = <15 0>;

   qcom,board-id = <0x01040708, 0>;

   qcom,board-id = <0x01ffff08, 0>;

   qcom,board-id = <8, 0x100>;

* MSM-ID

The qcom,msm-id entry specifies the MSM chipset, platform, hardware revision

and optional manufactured foundry.  It can optionally be an array of these to

indicate multiple hardware that use the same device tree.  It is expected that

the bootloader will use this information at boot-up to decide which device tree

to use when given multiple device trees, some of which may not be compatible

with the actual hardware.  It is the bootloader's responsibility to pass the

correct device tree to the kernel.

Format:

It is expected that the qcom,msm-id entry be at the top level of the device

tree structure.  The format can take one of the two forms below:

   qcom,msm-id = <chipset_foundry_id, platform_id, rev_id> [, <c2, p2, r2> ...]

   qcom,msm-id = <chipset_foundry_id, rev_id> [, <c2, r2> ...]

If the second format is used one must also define the board-id.

The "chipset_foundry_id" consists of three fields as below:

   bits 0-15  = The unique MSM chipset id.

   bits 16-23 = The optional foundry id. If bootloader doesn't find a device

		tree which has exact matching foundry-id with hardware it

		chooses the device tree with foundry-id = 0.

   bits 24-31 = Reserved.

Example:

   qcom,msm-id = <0x1007e 15 0>;

   qcom,board-id= <15 2>;

   qcom,msm-id = <0x1007e 0>;