The macros CONCAT(), MIN(), and MAX() are defined over and over again in
RIOT's code base. This de-duplicates the code by moving the macros to a
common place.
Add ATmega328P Xplained Mini board. The board is an official
development kit from MCHP based on the Arduino UNO, reduced
hardware, with a xplainedmini debugger and CDC ACM serial
converter.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
