ppc4xx: Add Io64 board support

Board support for the Guntermann & Drunck Io64.

Signed-off-by: Dirk Eibach <eibach@gdsys.de>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/boards.cfg b/boards.cfg
index c83d861..d13c47a 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -954,6 +954,7 @@
 gdppc440etx                  powerpc     ppc4xx      -                   gdsys
 intip                        powerpc     ppc4xx      intip               gdsys          -           intip:INTIB
 io                           powerpc     ppc4xx      405ep               gdsys
+io64                         powerpc     ppc4xx      405ex               gdsys
 iocon                        powerpc     ppc4xx      405ep               gdsys
 neo                          powerpc     ppc4xx      -                   gdsys
 icon                         powerpc     ppc4xx      -                   mosaixtech