audio maintainers update

av1474@comtv.ru bounces, and I havn't seen malc @ qemu-devel for quite a
while (anyone knows what is up?).  Adding myself as audio maintainer, so
audio patches don't fall through the cracks that easily.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

MAINTAINERS

@@ -638,6 +638,7 @@ Subsystems
 ----------
 Audio
 M: Vassili Karpov (malc) <av1474@comtv.ru>
+M: Gerd Hoffmann <kraxel@redhat.com>
 S: Maintained
 F: audio/
 F: hw/audio/