binman: Move state information into a new module

At present the control module has state information in it, since it is the
primary user of this. But it is a bit odd to have entries and other
modules importing control to obtain this information.

It seems better to have a dedicated state module, which control can use as
well. Create a new module using code from control and update other modules
to use it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
index 290e9ae..8671797 100644
--- a/tools/binman/ftest.py
+++ b/tools/binman/ftest.py
@@ -23,6 +23,7 @@
 import fdt_util
 import fmap_util
 import test_util
+import state
 import tools
 import tout
 
@@ -258,7 +259,7 @@
             retcode = self._DoTestFile(fname, map=map, update_dtb=update_dtb,
                                        entry_args=entry_args)
             self.assertEqual(0, retcode)
-            out_dtb_fname = control.GetFdtPath('u-boot.dtb')
+            out_dtb_fname = state.GetFdtPath('u-boot.dtb')
 
             # Find the (only) image, read it and return its contents
             image = control.images['image']