ARM: ixp4xx: convert remaining users to use gpiolib

A few call sites inside mach-ixp4xx were still using the custom
ixp4xx GPIO API with gpio_line_* accessors, convert all these
to use the standard gpiolib functions instead. Also attempt to
request and label all GPIOs before use. Move the GPIO requests
to per-machine device_initcalls() so we are not dependent on the
GPIO chip to be available at machine_init time.

Cc: Imre Kaloz <kaloz@openwrt.org>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/mach-ixp4xx/nslu2-setup.c

@@ -197,11 +197,8 @@ static void nslu2_power_off(void)
 {
 	/* This causes the box to drop the power and go dead. */
 
-	/* enable the pwr cntl gpio */
-	gpio_line_config(NSLU2_PO_GPIO, IXP4XX_GPIO_OUT);
-
-	/* do the deed */
-	gpio_line_set(NSLU2_PO_GPIO, IXP4XX_GPIO_HIGH);
+	/* enable the pwr cntl gpio and assert power off */
+	gpio_direction_output(NSLU2_PO_GPIO, 1);
 }
 
 static irqreturn_t nslu2_power_handler(int irq, void *dev_id)
@@ -223,6 +220,16 @@ static irqreturn_t nslu2_reset_handler(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static int __init nslu2_gpio_init(void)
+{
+	if (!machine_is_nslu2())
+		return 0;
+
+	/* Request the power off GPIO */
+	return gpio_request(NSLU2_PO_GPIO, "power off");
+}
+device_initcall(nslu2_gpio_init);
+
 static void __init nslu2_timer_init(void)
 {
     /* The xtal on this machine is non-standard. */