Updated MAINTAINERS for CAN bus related emulation as well.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Message-Id: <6d1b8db69efc4e5cfad702d2150e1960e8f63572.1600069689.git.pisa@cmp.felk.cvut.cz>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>