usb: gadget: configfs: Check USB configuration before adding

Ensure that the USB gadget is able to support the configuration being
added based on the number of endpoints required from all interfaces.  This
is for accounting for any bandwidth or space limitations.

Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Link: https://lore.kernel.org/r/1625908395-5498-3-git-send-email-wcheng@codeaurora.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>