Add a state variable that provides the current level of OS initialization.  This is needed by some logic that may attempt to run early in the start-up sequence, but cannot run if a sufficient level of initializaitn has not not yet occurred

drivers/modem/u-blox.c and include/nuttx/drivers/u-blox.h:  Add an upper half driver for the U-Blox Modem.  From  Vladimir Komendantskiy