HOTFIX:For Data loss on Nuttx serial w/ DMA &  GPIO Flow Control
HOTFIX:For Data loss on Nuttx serial w/ DMA &  GPIO Flow Control

   This hot fix essentialy revert commit 265af481209d60033f7cd4c4216048b1ce3eb435
   in NuttX/nuttx. The commit STM32 serial: Make input hardware flow-control work with RX DMA.
   From Jussi Kivilinna has broken the DMA on an STM32F4 in a yet TBD way.
   The symptoms are lost data on RX, the DMA count decrements but
   the data ia not written to memory. This looks to be introduced but the
   non circular DMA settings.

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