mpc5200: Add a3m071 board support

This patch adds support for the a3m071 board based on the
MPC5200.

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/boards.cfg b/boards.cfg
index ca9b12b..70a1569 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -473,6 +473,7 @@
 mpc5121ads_rev2              powerpc     mpc512x     mpc5121ads          freescale      -           mpc5121ads:MPC5121ADS_REV2
 cmi_mpc5xx                   powerpc     mpc5xx      cmi
 PATI                         powerpc     mpc5xx      pati                mpl
+a3m071                       powerpc     mpc5xxx     a3m071
 a4m072                       powerpc     mpc5xxx     a4m072
 BC3450                       powerpc     mpc5xxx     bc3450
 canmb                        powerpc     mpc5xxx