sh: r2dplus: Add support zimageboot

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/include/configs/r2dplus.h b/include/configs/r2dplus.h
index ade6f7c..8689513 100644
--- a/include/configs/r2dplus.h
+++ b/include/configs/r2dplus.h
@@ -24,6 +24,7 @@
 #define CONFIG_CMD_IDE
 #define CONFIG_CMD_EXT2
 #define CONFIG_DOS_PARTITION
+#define CONFIG_CMD_SH_ZIMAGEBOOT
 
 /* SCIF */
 #define CONFIG_SCIF_CONSOLE	1