binman: Move to absolute imports

At present binman sets the python path on startup so that it can access
the libraries it needs. If we convert to use absolute imports this is not
necessary.

Move binman to use absolute imports. This enables removable of the path
adjusting in Entry also.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/entry_test.py b/tools/binman/entry_test.py
index 277e10b..ca5bb0f 100644
--- a/tools/binman/entry_test.py
+++ b/tools/binman/entry_test.py
@@ -9,9 +9,9 @@
 import sys
 import unittest
 
-import entry
-import fdt
-import fdt_util
+from binman import entry
+from dtoc import fdt
+from dtoc import fdt_util
 import tools
 
 class TestEntry(unittest.TestCase):
@@ -37,11 +37,11 @@
             else:
                 reload(entry)
         else:
-            import entry
+            from binman import entry
 
     def testEntryContents(self):
         """Test the Entry bass class"""
-        import entry
+        from binman import entry
         base_entry = entry.Entry(None, None, None)
         self.assertEqual(True, base_entry.ObtainContents())