MAINTAINERS: add Eugenio Pérez as reviewer

Add myself as a reviewer of some VirtIO areas I'm interested.

Until this point I've been scanning manually the list looking for
series that touches this area.  Adding myself to make this task easier.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20240213182450.106796-1-eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>