Setting UIP_CONF_IPV6 to zero from the make build command line is
something that seems like it should ensure that IPv6 is disabled, but in
fact it actually *enables* IPv6. This seems counter intuitive, so this
patch changes the behavior of the makefiles to handle this case
properly.
MBXXX is a fake platform that actually include
all the platforms based on STM32W108 microcontroller.
Detection of the board is made at runtime, at the
expense of code size.
