The xHCI controller supports waking the system from S1-S4.
Thus specify that the deepest sleep state is S4 in _PRW.
Tested on Prodrive/hermes. The board now wakes from S4 as well by
pressing a key on the USB keyboard.
Change-Id: I0bb266e70ee6b4eb8922671b7d0078db0d29a1da
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49224
Reviewed-by: Christian Walter <christian.walter@9elements.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>