Implements intel_sibling_init() that is mostly superseded. Change-Id: I4956493d8c0c6b922343e060d2d2bd0ec20f5bb6 Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/55201 Reviewed-by: Angel Pons <th3fanbus@gmail.com> Reviewed-by: Arthur Heymans <arthur@aheymans.xyz> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>