binman: Support enabling debug in tests

The elf module can provide some debugging information to assist with
figuring out what is going wrong. This is also useful in tests. Update the
-D option so that it is passed through to tests as well.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/control.py b/tools/binman/control.py
index e9d48df..e175e8d 100644
--- a/tools/binman/control.py
+++ b/tools/binman/control.py
@@ -12,6 +12,7 @@
 import tools
 
 import command
+import elf
 import fdt
 import fdt_util
 from image import Image
@@ -89,6 +90,8 @@
 
     try:
         tout.Init(options.verbosity)
+        if options.debug:
+            elf.debug = True
         try:
             tools.SetInputDirs(options.indir)
             tools.PrepareOutputDir(options.outdir, options.preserve)