intel: export the length of SURFACE_STATE

6 on GEN6 and 8 on GEN7+.
diff --git a/icd/intel/view.h b/icd/intel/view.h
index 729f90d..e19935b 100644
--- a/icd/intel/view.h
+++ b/icd/intel/view.h
@@ -36,6 +36,7 @@
 
     /* SURFACE_STATE */
     uint32_t cmd[8];
+    XGL_UINT cmd_len;
 };
 
 struct intel_mem_view {
@@ -45,6 +46,7 @@
 
     /* SURFACE_STATE */
     uint32_t cmd[8];
+    XGL_UINT cmd_len;
 };
 
 struct intel_img_view {
@@ -57,6 +59,7 @@
 
     /* SURFACE_STATE */
     uint32_t cmd[8];
+    XGL_UINT cmd_len;
 };
 
 struct intel_rt_view {
@@ -66,6 +69,7 @@
 
     /* SURFACE_STATE */
     uint32_t cmd[8];
+    XGL_UINT cmd_len;
 };
 
 struct intel_ds_view {