regulator: gpio: explain detail of gpios-states

gpios-states is array, and default is 0
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Documentation/devicetree/bindings/regulator/gpio-regulator.txt

@@ -8,7 +8,8 @@ Required properties:
 Optional properties:
 - enable-gpio		: GPIO to use to enable/disable the regulator.
 - gpios			: GPIO group used to control voltage.
-- gpios-states		: gpios pin's initial states. 1 means HIGH
+- gpios-states		: gpios pin's initial states array. 0: LOW, 1: HIGH.
+			  defualt is LOW if nothing is specified.
 - startup-delay-us	: Startup time in microseconds.
 - enable-active-high	: Polarity of GPIO is active high (default is low).