Disable bl_upload command on non F4 tartgets
Disable bl_upload command on non F4 tartgets

   Upstream nuttx needs to have the flash programing support added.

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