This adds more helper functions that assist in calculating the checksum,
locating an ACPI table by signature, and updating an AML integer object.
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Daniel Schaefer <daniel.schaefer@hpe.com>
Signed-off-by: Nhi Pham <nhi@os.amperecomputing.com>
Acked-by: Leif Lindholm <leif@nuviainc.com>
Reviewed-by: Abner Chang <abner.chang@hpe.com>
c63a10ecb7