leds: Turn off led if blinking is disabled

When using the timer trigger and setting delay_on to 0, the led
will stay in whatever state is was in, while intuitively one
would expect it to turn off. This patch changes the behaviour to
turn it off.

Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>