docs/core-api: Add Fedora instructions for GCC plugins

Add an example of how to install the necessary packages for GCC
plugins on Fedora.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/core-api/gcc-plugins.rst

@@ -72,6 +72,10 @@ e.g., on Ubuntu for gcc-4.9::
 
 	apt-get install gcc-4.9-plugin-dev
 
+Or on Fedora::
+
+	dnf install gcc-plugin-devel
+
 Enable a GCC plugin based feature in the kernel config::
 
 	CONFIG_GCC_PLUGIN_CYC_COMPLEXITY = y