To be able to check during compilation that the number of endpoints provided by a USB peripheral is not exceeded, each interface class has to define the number of IN and OUT endpoints it requires.
This commit changes the name of the requests over the control endpoints
to control requests instead of setup requests. This is a terminology fix
to follow the USB specification more closely as technically only the
first stage of a control request is named setup which contains a setup
packet. The whole transfer is a control transfer.
