Currently we copy over a number of usb_device values stored in the on stack
struct usb_device probed in usb_scan_device() to the final driver-model managed
struct usb_device in usb_child_pre_probe() through usb_device_platdata, and
then call usb_select_config() to fill in the rest.

There are 3 problems with this approach:

1) It does not fill in enough fields before calling usb_select_config(),
specifically it does not fill in ep0's maxpacketsize causing a div by zero
exception in the ehci driver.

2) It unnecessarily redoes a number of usb requests making usb probing slower

3) Calling usb_select_config() a second time fails on some usb-1 devices
plugged into usb-2 hubs, causing u-boot to not recognize these devices.

This commit fixes these issues by removing (*) the usb_select_config() call
from usb_child_pre_probe(), and instead of copying over things field by field
through usb_device_platdata, store a pointer to the in stack usb_device
(which is still valid when usb_child_pre_probe() gets called) and copy
over the entire struct.

*) Except for devices which are explictly instantiated through device-tree
rather then discovered through usb_scan_device() such as emulated usb devices
in the sandbox.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Simon Glass <sjg@chromium.org>