USB: fsl_usb2_udc: Report disconnect before unbinding

USB: fsl_usb2_udc: Report disconnect before unbinding

Gadgets disable endpoints in their disconnect callbacks, so
we must call disconnect before unbinding.

The patch fixes following badness:

root@b1:~# insmod fsl_usb2_udc.ko
Freescale High-Speed USB SOC Device Controller driver (Apr 20, 2007)
root@b1:~# insmod g_ether.ko
g_ether gadget: using random self ethernet address
g_ether gadget: using random host ethernet address
usb0: MAC 26:07:ba:c0:44:33
usb0: HOST MAC 96:81:0c:05:4d:e3
g_ether gadget: Ethernet Gadget, version: Memorial Day 2008
g_ether gadget: g_ether ready
fsl-usb2-udc: bind to driver g_ether
g_ether gadget: high speed config #1: CDC Ethernet (ECM)
root@b1:~# rmmod g_ether.ko
------------[ cut here ]------------
Badness at drivers/usb/gadget/composite.c:871
[...]
NIP [e10c3454] composite_unbind+0x24/0x15c [g_ether]
LR [e10aa454] usb_gadget_unregister_driver+0x13c/0x164 [fsl_usb2_udc]
Call Trace:
[df145e80] [ffffff94] 0xffffff94 (unreliable)
[df145eb0] [e10aa454] usb_gadget_unregister_driver+0x13c/0x164 [fsl_usb2_udc]
[df145ed0] [e10c4c40] usb_composite_unregister+0x3c/0x4c [g_ether]
[df145ee0] [c006bcc0] sys_delete_module+0x130/0x19c
[df145f40] [c00142d8] ret_from_syscall+0x0/0x38
[...]
unregistered gadget driver 'g_ether'

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>