linuxkpi: Add woken_wake_function() and wait_woken()

They are used by the i915 DRM driver starting with Linux 6.7.

(struct wait_queue)->flags is no longer always zero. I wonder if some
code relied on this...

Reviewed by: markj
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D48755