sphinx: add Yocto project logo

(From yocto-docs rev: 125c70b04a28bf095ed1cd8273ebdc7d1d0b5cfd)

Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/conf.py

@@ -51,6 +51,8 @@ master_doc = 'index'
 #
 html_theme = 'sphinx_rtd_theme'
 
+html_logo = 'sphinx-static/YoctoProject_Logo_RGB.jpg'
+
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".