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/dtoc/fdt.py b/tools/dtoc/fdt.py
index 1b7b730..188490b 100644
--- a/tools/dtoc/fdt.py
+++ b/tools/dtoc/fdt.py
@@ -8,10 +8,10 @@
 import struct
 import sys
 
-import fdt_util
+from dtoc import fdt_util
 import libfdt
 from libfdt import QUIET_NOTFOUND
-import tools
+from patman import tools
 
 # This deals with a device tree, presenting it as an assortment of Node and
 # Prop objects, representing nodes and properties, respectively. This file