extcon: usb-gpio: add support for ACPI gpio interface

GPIO resource could be retrieved through APCI as well.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Felipe Balbi <balbi@kernel.org>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

drivers/extcon/extcon-usb-gpio.c

@@ -27,6 +27,7 @@
 #include <linux/pm_wakeirq.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
+#include <linux/acpi.h>
 
 #define USB_GPIO_DEBOUNCE_MS	20	/* ms */
 
@@ -92,7 +93,7 @@ static int usb_extcon_probe(struct platform_device *pdev)
 	struct usb_extcon_info *info;
 	int ret;
 
-	if (!np)
+	if (!np && !ACPI_HANDLE(dev))
 		return -EINVAL;
 
 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);