usb: gadget: libcomposite: add epautoconf.c to libcomposite

This patch adds epautoconf.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>