etl

804a401a - Automatically detect native endianness for IAR compiler platform. (#612)

Automatically detect native endianness for IAR compiler platform. (#612) * Auto detect native endianness for IAR compiler platform. References: - [IAR C/C++ Development Guide Compiling and Linking for Arm Limited’s **Arm**® Cores](https://wwwfiles.iar.com/arm/webic/doc/ewarm_developmentguide.enu.pdf) - [IAR C/C++ Compiler User Guide for Microchip Technology’s **AVR** Microcontroller Family](https://wwwfiles.iar.com/AVR/webic/doc/EWAVR_CompilerGuide.pdf) * Fix spelling mistake.