intel: export more shader info

Needed for 3DSTATE_WM and 3DSTATE_PS.
diff --git a/icd/intel/shader.c b/icd/intel/shader.c
index de89262..c026a84 100644
--- a/icd/intel/shader.c
+++ b/icd/intel/shader.c
@@ -55,6 +55,7 @@
         break;
     case 'w':
         sh->out_count = 1;
+        sh->surface_count = 1;
         break;
     default:
         break;