Current there is no way to split code between ATmega and ATxmega in
drivers. This differentiate AVR8 cores into MEGAs and XMEGAs.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
Add ATxmega common files and cpu definitions.
This works was originally developed by @Josar. The 2018 version
were port to 2021 mainline.
This version changes original port to have only the atxmega CPU
definition. With that, all family can be accomodated.
Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>