maintainer update: add support for more AVR microcontrollers

[Eric Christopher]

> all but happy about that change (as it is the first time where a
> suffix letter really makes a difference for the device), but for
> whatever reason, that's their marketing decision.

Sounds reasonable.

> Documentation for the entire toolchain is mainly maintained as part of
> the avr-libc project:
>
> http://www.nongnu.org/avr-libc/user-manual/index.html

This is bad. You should consider documenting the binutils options in  
the binutils manual.

-eric