patman: Move library functions into a library directory

The patman directory has a number of modules which are used by other tools
in U-Boot. This makes it hard to package the tools using pypi since the
common files must be copied along with the tool that uses them.

To address this, move these files into a new u_boot_pylib library. This
can be packaged separately and listed as a dependency of each tool.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/control.py b/tools/binman/control.py
index abe01b7..9b183ed 100644
--- a/tools/binman/control.py
+++ b/tools/binman/control.py
@@ -12,14 +12,14 @@
 import re
 
 import sys
-from patman import tools
 
 from binman import bintool
 from binman import cbfs_util
-from patman import command
 from binman import elf
 from binman import entry
-from patman import tout
+from u_boot_pylib import command
+from u_boot_pylib import tools
+from u_boot_pylib import tout
 
 # These are imported if needed since they import libfdt
 state = None