Cleanup and added copyright notices

...32gg/efm32gg332f1024_wandstem/interfaces-impl/cstimer.cpp

...g/efm32gg332f1024_wandstem/interfaces-impl/gpio_timer.cpp

...2gg/efm32gg332f1024_wandstem/interfaces-impl/gpio_timer.h

...4_wandstem/interfaces-impl/high_resolution_timer_base.cpp

...024_wandstem/interfaces-impl/high_resolution_timer_base.h

...fm32gg332f1024_wandstem/interfaces-impl/timer_interface.h

...gg332f1024_wandstem/interfaces-impl/transceiver_timer.cpp

...32gg332f1024_wandstem/interfaces-impl/transceiver_timer.h