usb: gadget: libcomposite: move config.c into libcomposite

This patch moves config.c into libcomposite and updates all gadgets.

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/drivers/usb/gadget/config.c b/drivers/usb/gadget/config.c
index 7542a72c..e3a9892 100644
--- a/drivers/usb/gadget/config.c
+++ b/drivers/usb/gadget/config.c
@@ -12,6 +12,7 @@
 #include <linux/errno.h>
 #include <linux/slab.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/list.h>
 #include <linux/string.h>
 #include <linux/device.h>
@@ -53,7 +54,7 @@
 	}
 	return dest - (u8 *)buf;
 }
-
+EXPORT_SYMBOL_GPL(usb_descriptor_fillbuf);
 
 /**
  * usb_gadget_config_buf - builts a complete configuration descriptor
@@ -106,6 +107,7 @@
 	cp->bmAttributes |= USB_CONFIG_ATT_ONE;
 	return len;
 }
+EXPORT_SYMBOL_GPL(usb_gadget_config_buf);
 
 /**
  * usb_copy_descriptors - copy a vector of USB descriptors
@@ -155,4 +157,4 @@
 
 	return ret;
 }
-
+EXPORT_SYMBOL_GPL(usb_copy_descriptors);