Dmitry has been renamed

My surname has changed due to marriage. Change MAINTAINERS entry
and add .mailmap entry to reflect that.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>