aspeed: Support for ast2500 Eval Board

ast2500 Eval Board device tree and board specific configuration.
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/aspeed/evb_ast2500/Makefile b/board/aspeed/evb_ast2500/Makefile
new file mode 100644
index 0000000..4564098
--- /dev/null
+++ b/board/aspeed/evb_ast2500/Makefile
@@ -0,0 +1 @@
+obj-y += evb_ast2500.o