gps: fix thread initialization under posix
gps: fix thread initialization under posix

under NuttX the argc in task_main_trampoline contains two arguments,
but on linux only one.

mje-nz/PX4-Firmware,darknight-007/Firmware,dagar/Firmware,krbeverx/Firmware,mcgill-robotics/Firmware,darknight-007/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,acfloria/Firmware,mcgill-robotics/Firmware,mje-nz/PX4-Firmware,jlecoeur/Firmware,dagar/Firmware,acfloria/Firmware,jlecoeur/Firmware,Aerotenna/Firmware,krbeverx/Firmware,krbeverx/Firmware,PX4/Firmware,PX4/Firmware,dagar/Firmware,mcgill-robotics/Firmware,mje-nz/PX4-Firmware,PX4/Firmware,acfloria/Firmware,mcgill-robotics/Firmware,dagar/Firmware,jlecoeur/Firmware,dagar/Firmware,Aerotenna/Firmware,darknight-007/Firmware,Aerotenna/Firmware,acfloria/Firmware,PX4/Firmware,krbeverx/Firmware,acfloria/Firmware,PX4/Firmware,darknight-007/Firmware,acfloria/Firmware,jlecoeur/Firmware,mcgill-robotics/Firmware,krbeverx/Firmware,acfloria/Firmware,jlecoeur/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,PX4/Firmware,darknight-007/Firmware,mcgill-robotics/Firmware,dagar/Firmware,mje-nz/PX4-Firmware,jlecoeur/Firmware,mcgill-robotics/Firmware,krbeverx/Firmware,jlecoeur/Firmware,Aerotenna/Firmware,jlecoeur/Firmware,PX4/Firmware,mje-nz/PX4-Firmware,dagar/Firmware,krbeverx/Firmware,Aerotenna/Firmware