MAINTAINERS: update viafb entry

MAINTAINERS: update viafb entry

List the files that got recently moved to include/linux.
Add myself as a maintainer and remove Scott as his email address is
no longer valid and he has shown no interest in maintaining viafb.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Joseph Chan <JosephChan@via.com.tw>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Harald Welte <laforge@gnumonks.org>