USB: compile-time endpoints allocation

USB: compile-time endpoints allocation

If we want to use many USB device drivers at the same time, we need to
properly allocate the endpoints among different drivers to avoid
conflicts (different drivers using the same endpoint).

Perform this allocation at compile-time according to the drivers enabled
in the project's configuration.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4377 38d2e660-2303-0410-9eaa-f027e97ec537