intel: update genhw headers

Lots of renames and Gen8 support.  Changes verified by "gcc -E" and diff to
have some confidence that I did not mess up.
diff --git a/icd/intel/cmd_barrier.c b/icd/intel/cmd_barrier.c
index bc36945..819b351 100644
--- a/icd/intel/cmd_barrier.c
+++ b/icd/intel/cmd_barrier.c
@@ -166,7 +166,7 @@
     if ((old_caches & DATA_WRITE_CACHE) &&
         (new_caches & ~(DATA_READ_CACHE | DATA_WRITE_CACHE))) {
         if (cmd_gen(cmd) >= INTEL_GEN(7))
-            flags |= GEN7_PIPE_CONTROL_DC_FLUSH_ENABLE;
+            flags |= GEN7_PIPE_CONTROL_DC_FLUSH;
     }
 
     if (new_caches & SAMPLER_CACHE)
@@ -233,7 +233,7 @@
     }
 
     if (output_mask & XGL_MEMORY_OUTPUT_SHADER_WRITE_BIT) {
-        flush_flags |= GEN7_PIPE_CONTROL_DC_FLUSH_ENABLE;
+        flush_flags |= GEN7_PIPE_CONTROL_DC_FLUSH;
     }
     if (output_mask & XGL_MEMORY_OUTPUT_COLOR_ATTACHMENT_BIT) {
         flush_flags |= GEN6_PIPE_CONTROL_RENDER_CACHE_FLUSH;