USB: Fix LPM disable count mismatch on driver unbind.

When a user runs `echo 0 > bConfigurationValue` for a USB 3.0 device,
usb_disable_device() is called.  This function disables all drivers,
deallocates interfaces, and sets the device configuration value to 0
(unconfigured).

With the new scheme to ensure that unconfigured devices have LPM
disabled, usb_disable_device() must call usb_unlocked_disable_lpm() once
it unconfigures the device.

This commit should be backported to kernels as old as 3.5, that contain
the commit 8306095f "USB: Disable USB
3.0 LPM in critical sections."

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org