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19371: sys/usbus: check for the number of required and provided EPs in static configurations r=dylad a=gschorcht ### Contribution description This PR provides a static check at compile time whether the number of EPs required in a static configuration does not exceed the number of EPs provided by the USB device. #### Background In issue #19359 the problem was reported that `usbus_cdc_ecm` didn't work together with `stdio_cdc_acm` on some STM32 boards. The reason for some of the boards was simply that the application tried to allocate more EPs than available and simply ignored this and just didn't work. #### Solution Since `auto_init_usb` uses a static configuration with exactly one USBUS stack instance and one USB device, at least in case `auto_init` is used a static check can be carried out to make sure that the number of EPs required by the application doesn't exceed the number of EPs provided by the USB device. For this purpose, each `usbus_*` module defines the number of IN and OUT EPs required by that module. Each USB device driver defines the number of EPs provided by USB device if it differs from the default of 8 EPs. During the auto initialization the total number of required IN and OUT EPs is then compared with the number of EPs provided by the USB device using a static assert. ### Testing procedure 1. Green CI 2. Compilation of ```python USEMODULE='stdio_cdc_acm' BOARD=nucleo-f439zi make -j8 -C tests/usbus_cdc_ecm ``` should lead to compilation error ```python sys/auto_init/usb/auto_init_usb.c:81:1: error: static assertion failed: "Number of required IN endpoints exceeded" _Static_assert(USBUS_EP_IN_REQUIRED_NUMOF <= USBDEV_NUM_ENDPOINTS, ^~~~~~~~~~~~~~ Makefile.base:146: recipe for target 'tests/usbus_cdc_ecm/bin/nucleo-f439zi/auto_init_usbus/auto_init_usb.o' failed ``` while compilation of ``` USEMODULE='stdio_cdc_acm' BOARD=nucleo-f767zi make -j8 -C tests/usbus_cdc_ecm ``` should work. ### Issues/PRs references Fixes issue #19359 partially. 19382: tests/pkg_nanors: use static allocation r=benpicco a=benpicco Co-authored-by: Gunar Schorcht <gunar@schorcht.net> Co-authored-by: Benjamin Valentin <benpicco@beuth-hochschule.de>