MAINTAINERS: Document virtex_ml507 machine

Place it in alphabetical order, there is a separate section for sharing
ppc4xx devices now.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/MAINTAINERS b/MAINTAINERS
index dca8753..78d4ff2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -403,6 +403,12 @@
 S: Supported
 F: hw/spapr*
 
+virtex_ml507
+M: Edgar E. Iglesias <edgar.iglesias@gmail.com>
+L: qemu-ppc@nongnu.org
+S: Odd Fixes
+F: hw/virtex_ml507.c
+
 SH4 Machines
 ------------
 R2D