libvpx: name the supported formats.

Signed-off-by: Sagaert Johan <sagaert.johan@proximus.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libvpx/Config.in

@@ -3,7 +3,7 @@ config BR2_PACKAGE_LIBVPX
 	depends on BR2_TOOLCHAIN_HAS_THREADS
 	help
 	  A high-quality, open video format that's freely available to
-	  everyone.
+	  everyone. Supports the VP8 and VP9 formats.
 
 	  http://webmproject.org