px4fmu-v5:board_config clean up
px4fmu-v5:board_config clean up

   Removed unused headers and placed the __BEGIN_DECLS where it belonged

dagar/Firmware,acfloria/Firmware,PX4/Firmware,acfloria/Firmware,dagar/Firmware,Aerotenna/Firmware,Aerotenna/Firmware,dagar/Firmware,jlecoeur/Firmware,krbeverx/Firmware,jlecoeur/Firmware,acfloria/Firmware,krbeverx/Firmware,mcgill-robotics/Firmware,jlecoeur/Firmware,acfloria/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,mcgill-robotics/Firmware,mje-nz/PX4-Firmware,PX4/Firmware,acfloria/Firmware,jlecoeur/Firmware,mje-nz/PX4-Firmware,jlecoeur/Firmware,jlecoeur/Firmware,mje-nz/PX4-Firmware,acfloria/Firmware,PX4/Firmware,PX4/Firmware,jlecoeur/Firmware,krbeverx/Firmware,krbeverx/Firmware,jlecoeur/Firmware,mje-nz/PX4-Firmware,PX4/Firmware,mcgill-robotics/Firmware,krbeverx/Firmware,mcgill-robotics/Firmware,mcgill-robotics/Firmware,dagar/Firmware,mje-nz/PX4-Firmware,acfloria/Firmware,mcgill-robotics/Firmware,PX4/Firmware,mje-nz/PX4-Firmware,Aerotenna/Firmware,PX4/Firmware,krbeverx/Firmware,Aerotenna/Firmware,krbeverx/Firmware,dagar/Firmware,Aerotenna/Firmware,dagar/Firmware,mcgill-robotics/Firmware,dagar/Firmware,Aerotenna/Firmware