Add a bare bones framework that will do nothing more than support configuration for the Atmel SAMV71 Xplained Ultra board.  Very much a work in progress.

Rename all use of up_boardinitialize().  Should not use common microprocessing naming convention but rather the microprocessor-specific naming conventioni

configs/: board function prototypes are now in include/nuttx/board.h.  Remove from board header file; Add inclusion of nuttx/board.h to all files referencing board functions

PIC32MZ: Make sure that the microMIPS ISA is selected on all common MIPS32 assembly files when the PIC21MZ is selected

MIPS:  Add some build support for the M14K and also for the PIC32MZ Starter Kit.  Still a long way to go

Add basic board support for the PIC32MZ (can't build yet of course because there is not yet any PIC32MZ support)

Add path for Pinguino tools.  Need to be careful because bin directory has an incompatible make.exe in it

pic32mx-starterkit: Move scripts to common directory.  Pinguino build needs to use a different linker script

pic32mx-starterkit: Move scripts to common directory.  Pinguino build needs to use a different linker script