HID: cp2112: can't be used without gpio support

Add Kconfig driver dependency on GPIOLIB.

Reported-by: fengguang.wu@intel.com
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 5eaf0db..669cc19 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -177,7 +177,7 @@
 
 config HID_CP2112
 	tristate "Silicon Labs CP2112 HID USB-to-SMBus Bridge support"
-	depends on USB_HID && I2C
+	depends on USB_HID && I2C && GPIOLIB
 	---help---
 	Support for Silicon Labs CP2112 HID USB to SMBus Master Bridge.
 	This is a HID device driver which registers as an i2c adapter