Fix the pin triggering on stm32f100 chip

    * config/arm/chips/stm32f100/chipsupport.h: The pin initialisation
        was broken, not setting to output correctly.
Merge branch 'master' of github.com:mageec/beebs
Merge pull request #25 from jpallister/master

Fix pin triggering on STM32VLDISCOVERY board