intel: do not require render node

We can use the primary node for GPUs with an X display associated.
diff --git a/icd/intel/intel.c b/icd/intel/intel.c
index c248460..f7b83b9 100644
--- a/icd/intel/intel.c
+++ b/icd/intel/intel.c
@@ -106,10 +106,11 @@
         struct intel_gpu *gpu;
 
         primary_node = icd_drm_get_devnode(dev, ICD_DRM_MINOR_LEGACY);
-        render_node = icd_drm_get_devnode(dev, ICD_DRM_MINOR_RENDER);
-        if (!primary_node || !render_node)
+        if (!primary_node)
             continue;
 
+        render_node = icd_drm_get_devnode(dev, ICD_DRM_MINOR_RENDER);
+
         ret = intel_gpu_add(dev->devid, primary_node, render_node, &gpu);
         if (ret == XGL_SUCCESS) {
             pGpus[count++] = (XGL_PHYSICAL_GPU) gpu;