This change adds a helper function cpu_get_lapic_addr() that returns LOCAL_APIC_ADDR for x86. It also adds a weak default implementation which returns 0 if platform does not support LAPIC. This is being done in preparation to move all ACPI table support in coreboot out of arch/x86. BUG=b:155428745 Change-Id: I4d9c50ee46804164712aaa22be1b434f800871ec Signed-off-by: Furquan Shaikh <furquan@google.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/40929 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-by: Duncan Laurie <dlaurie@chromium.org>