acpi: Generate object for coreboot table region

acpi: Generate object for coreboot table region

Generate an object to describe the coreboot table region in ACPI
with the HID "CORE0000" so it can be used by kernel drivers.

To keep track of the "CORE" HID usage add them to an enum and add
a function to generate the HID in AML:  Name (_HID, "CORExxxx")

BUG=chromium:589817
BRANCH=none
TEST=build and boot on chell, dump SSDT to verify contents:

Device (CTBL)
{
    Name (_HID, "CORE0000")  // _HID: Hardware ID
    Name (_UID, Zero)  // _UID: Unique ID
    Method (_STA, 0, NotSerialized)  // _STA: Status
    {
        Return (0x0F)
    }
    Name (_CRS, ResourceTemplate ()  // _CRS: Current Resource Settings
    {
        Memory32Fixed (ReadOnly,
            0x7AB84000,         // Address Base
            0x00008000,         // Address Length
            )
    })
}

Change-Id: I2c681c1fee02d52b8df2e72f6f6f0b76fa9592fb
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://review.coreboot.org/16056
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>