Minimize use of hard-coded value for acpi_table_header->length to soft
code. Replace length of acpi_header_t with sizeof(acpi_fadt_t).
Change-Id: Ibcae72e8f02497719fcd3f180838557e8e9abd38
Signed-off-by: Himanshu Sahdev <himanshusah@hcl.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35540
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Richard Spiegel <richard.spiegel@silverbackltd.com>