ec/lenovo/h8: Implement sticky Fn option.

Useful for accessibility.

Sticky modifier (sticky Fn) is a behaviour of modifier key when
you don't have to hold it pressed to achieve the result. E.g.
with normal Fn brightness up is:
<Press Fn> <Press Home> <Despress Home> <Depress Fn>
With sticky Fn you can do:
<Press Fn> <Depress Fn> <Press Home> <Despress Home>

Change-Id: I4da5adcea02428d936023891de08684cae77c44e
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/4661
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

src/mainboard/lenovo/x60/cmos.layout

@@ -113,6 +113,7 @@ entries
 1081         1       e       1        bluetooth
 1082         1       e       1        wwan
 1085         1       e       1        fn_ctrl_swap
+1086         1       e       1        sticky_fn
 # -----------------------------------------------------------------
 
 enumerations