Comparing to the Linux driver there is still one missing feature.
The Linux driver finds and enables "Embedded Controller" item in
the 0x11 group if it's not enabled yet.
I tested the new method, Torfinn Ingolfsen tested the old method
and helped to fix several bugs in the earlier versions of the patch.
Tested by: Torfinn Ingolfsen <torfinn.ingolfsen@getmail.no>
Reviewed by: rpaulo
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D8227
2698bbbb5a