This fixes a bug were a SoC does not have a clockdivN register
   and passes a 0 for the init value. This prevents overflow of
   the 0 decremented to -1 (0xffffffff) spilling over to other
   clockdivN feilds.

  Remove magic numbers from code, documented the use of
  undocumented bits.

  Remove comments and code that were not appropriate for this
  hardware.

  Removed ifdef that's that were always compiled and removed code
  blocks that were never compiled.

  Ensure proper access order to hardware.
  Per the reference manual: disable endpoints prior to configuring buffer
  descriptor, then enable endpoints
  Reorganize interrupt processing order to offload data after processing
  errors.

  Reorganize initialization so that there is a clear initialization phase,
  reset phase for both the hardware and software structures.

  By breaking the initialization into smaller pieces, the reset interrupt
  only resets the resources within the controller that should be reset.

  Rework suspend and resume logic so they perform properly

  Made attach and detach functions optional. As they do not make sense for
  a bus powered device.

  Ensured the calls to up_usbinitalize up_usbuninitalize do not violate the
  USB spec.

   Allow the board config to define the USBOTG-FS to have Read access to
   FLASH.

   The hardware reset state of the the MPU precludes any bus
   masters other then DMA access to memory. Unfortunately
   USB and SDHC have there own DMA and will not have access to
   memory in the default reset state.

   This change disabled the MPU if present on system startup.

MTD FLASH drivers:  The byte write method of several drivers had a cloned error:  It was not locking the bus while performing byte write operations.

libfflush remove extra semicolon

Approved-by: Gregory Nutt <gnutt@nuttx.org>

Comment out most of 430060e9.  Clean-up some dependencies in top-level Makefile

This reverts commit 430060e9.

That commit has some unexpected side-effects

tools/:  Add initialconfig.c so that perhaps in the future we will be able to use this to generate a new configuration from scratch (rather than having to derive new configurations from existing configurations)

nucleo-f4x1re User LEDS: Issue #51 reports compilation problems with stm32_userled.c.  Reported by Gappi92.

Tiva SSI:  Resolves issue 52 'Copy-Paste error in tiva_ssibus_initialize()' submitted by Aleksandr Kazantsev.

Makefiles.*: It should be possible to run 'make menuconfig' with no .config and no Make.defs file.  This change removes the dependency on Make.defs, but does not solve the problem of the missing .config file.  Without a .config file, it is not currently possible for the Makefile.* to correctly setup up the symbolic links to directories.

pthread robust mutexes:  Fix memmory trashing problem:  the main task may also use mutexes; need to check thread type before accessing pthread-specific mutex data structures.  Problem noted by Jussi Kivilinna.