Add HP EliteBook 8560w

Iru Cai's port from Gerrit:
https://review.coreboot.org/c/coreboot/+/39398



Now with the proper MXM structure, which removes the 30 second POST
delay. Tested with i7-2670QM, Quadro 2000M and 32GB RAM.

Signed-off-by: Riku Viitanen <riku.viitanen@protonmail.com>