Send netlink message notifications using a uevent with
subsystem=xt_idletimer
INTERFACE=...
STATE={active,inactive}
instead of needing a new netlink message type.
Revert the netlink.h change added by commit
beb914e987
Change-Id: I6881936bf754f3367ff3c8f6c1e9661cec0357d4
Signed-off-by: JP Abgrall <jpa@google.com>