st/xorg: Detect libkms with scons too.
diff --git a/scons/gallium.py b/scons/gallium.py
index 3c0ff90..7374cf5 100644
--- a/scons/gallium.py
+++ b/scons/gallium.py
@@ -559,6 +559,7 @@
     pkg_config_modules(env, 'x11', ['x11', 'xext'])
     pkg_config_modules(env, 'dri', ['libdrm'])
     pkg_config_modules(env, 'xorg', ['xorg-server'])
+    pkg_config_modules(env, 'kms', ['libkms'])
 
     # Custom builders and methods
     env.Tool('custom')