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/patman/patchstream.py b/tools/patman/patchstream.py
index df3eb74..4052975 100644
--- a/tools/patman/patchstream.py
+++ b/tools/patman/patchstream.py
@@ -9,10 +9,10 @@
 import shutil
 import tempfile
 
-import command
-import commit
-import gitutil
-from series import Series
+from patman import command
+from patman import commit
+from patman import gitutil
+from patman.series import Series
 
 # Tags that we detect and remove
 re_remove = re.compile('^BUG=|^TEST=|^BRANCH=|^Review URL:'