patman: Move to absolute imports

At present patman 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 patman to use absolute imports. This requires changes in tools which
use the patman libraries (which is most of them).

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/fmap_util.py b/tools/binman/fmap_util.py
index d0f956b..25fe60a 100644
--- a/tools/binman/fmap_util.py
+++ b/tools/binman/fmap_util.py
@@ -10,7 +10,7 @@
 import struct
 import sys
 
-import tools
+from patman import tools
 
 # constants imported from lib/fmap.h
 FMAP_SIGNATURE = b'__FMAP__'