Doxygen: exclude drivers/libtsm

drivers/libtsm includes a bunch of Doxygen comments, and worst of all, a
"@mainpage" tag controlling Doxygen's main page. Since libtsm isn't really
part of the API we intend to advertise, let's exclude this directory from
being scanned by doxygen.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

Doxyfile

@@ -607,7 +607,7 @@ RECURSIVE              = YES
 # Note that relative paths are relative to the directory from which doxygen is
 # run.
 
-EXCLUDE                =
+EXCLUDE                = drivers/libtsm
 
 # The EXCLUDE_SYMLINKS tag can be used to select whether or not files or
 # directories that are symbolic links (a Unix file system feature) are excluded