TWR K70 msd bootloader

The TWR-K70 MSD bootloader application is based on the Application Note source code AN4368 and has the same functionality presented in the document (for more details refer to Referenced Documents). Some important modifications were made in order to complete the migration process of the mentioned source code to be used with the TWR-K70F102M that implements a MK70FN1M0VMJ12 device on board.