usb: gadget: move bind callback into driver struct usb_composite_driver

It was moved to be an argument in 07a18bd716ed5 ("usb gadget: don't
save bind callback in struct usb_composite_driver"). The reason was to
avoid the section missmatch. The warning was shown because ->bind is
marked as __init becuase it is a one time init. The warning can be also
suppresed by whitelisting the variable i.e. rename it to lets say _probe.

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 9d8c3b6..3153f73 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -257,12 +257,16 @@
  *	not set.
  * @dev: Template descriptor for the device, including default device
  *	identifiers.
- * @strings: tables of strings, keyed by identifiers assigned during bind()
+ * @strings: tables of strings, keyed by identifiers assigned during @bind
  *	and language IDs provided in control requests
  * @max_speed: Highest speed the driver supports.
  * @needs_serial: set to 1 if the gadget needs userspace to provide
  * 	a serial number.  If one is not provided, warning will be printed.
- * @unbind: Reverses bind; called as a side effect of unregistering
+ * @bind: (REQUIRED) Used to allocate resources that are shared across the
+ *	whole device, such as string IDs, and add its configurations using
+ *	@usb_add_config(). This may fail by returning a negative errno
+ *	value; it should return zero on successful initialization.
+ * @unbind: Reverses @bind; called as a side effect of unregistering
  *	this driver.
  * @disconnect: optional driver disconnect method
  * @suspend: Notifies when the host stops sending USB traffic,
@@ -271,9 +275,9 @@
  *	before function notifications
  *
  * Devices default to reporting self powered operation.  Devices which rely
- * on bus powered operation should report this in their @bind() method.
+ * on bus powered operation should report this in their @bind method.
  *
- * Before returning from bind, various fields in the template descriptor
+ * Before returning from @bind, various fields in the template descriptor
  * may be overridden.  These include the idVendor/idProduct/bcdDevice values
  * normally to bind the appropriate host side driver, and the three strings
  * (iManufacturer, iProduct, iSerialNumber) normally used to provide user
@@ -291,6 +295,7 @@
 	enum usb_device_speed			max_speed;
 	unsigned		needs_serial:1;
 
+	int			(*bind)(struct usb_composite_dev *cdev);
 	int			(*unbind)(struct usb_composite_dev *);
 
 	void			(*disconnect)(struct usb_composite_dev *);