This commit adds a barbones FTDI FT80x driver. It is untested (I don't even...

This commit adds a barbones FTDI FT80x driver.  It is untested (I don't even have hardware yet and, hence, it is marked as EXPERIMENTAL

Squashed commit of the following:

    drivers/lcd:  Finishes off basic FT80X.  Still missing some niceties.
    drivers/lcd: Rethink FT80X display list interface.
    drivers/lcd:  More FT800x display list logic.  Still not complete.
    drivers/lcd:  Add some basic FT80x initialization logic.
    drivers/lcd:  Add ft80x display list IOCTL framework.  Still missing low level display list operations.
    drivers/lcd:  FT80x driver cannot be a standard LCD driver but must, instead, be a custom character driver.
    drivers/lcd:  Add FT800 co-processor commands and display list helpers.
    drivers/lcd:  Add SPI interface and framework for the initialization and the basic LCD driver.
    drivers/lcd:  Add beginnings of some FT80x implementation.
    drivers/lcd:  Add definitions for the FTDI FT801 part
    include/nuttx/lcd/ft800.h:  Add initial FT800 interface definition.
    drivers/lcd:  Add ft800 header file.