mailmap: add aliases for Dmitry Safonov

I don't work for Virtuozzo or Samsung anymore and I've noticed that they
have started sending annoying html email-replies.

And I prioritize my personal emails over work email box, so while at it
add an entry for Arista too - so I can reply faster when needed.

Link: http://lkml.kernel.org/r/20190827220346.11123-1-dima@arista.com


Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>