* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
drivers/lcd/ft80x: ACTIVE host command appears to be formatted differently than other host commands; Fix ROM CHIPID. Appears to be big-ending, BCD.
drivers/lcd/ft80x: Fix some compile issues when debug features are enabled.
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.