python3: patch setup.py so that it does not include system include dirs

Seems that the Python C extensions were being
(or at least trying to be) build using '/usr/include' as the first
include folder.

Seems this issue was already fixed on MacOS X and now we've extended
it for our case.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

lang/python3/patches/120-do-not-add-include-dirs-when-cross-compiling.patch

@@ -0,0 +1,14 @@
+diff --git a/setup.py b/setup.py
+index 93f390f..ace1494 100644
+--- a/setup.py
++++ b/setup.py
+@@ -461,7 +461,8 @@ class PyBuildExt(build_ext):
+                         add_dir_to_list(dir_list, directory)
+ 
+         if os.path.normpath(sys.base_prefix) != '/usr' \
+-                and not sysconfig.get_config_var('PYTHONFRAMEWORK'):
++                and not sysconfig.get_config_var('PYTHONFRAMEWORK') \
++                and not cross_compiling:
+             # OSX note: Don't add LIBDIR and INCLUDEDIR to building a framework
+             # (PYTHONFRAMEWORK is set) to avoid # linking problems when
+             # building a framework with different architectures than