i965: Make INTEL_DEBUG=mip print out whether HiZ is enabled.

We only enable HiZ for miplevels which are aligned on 8x4 blocks.  When
debugging HiZ failures, it's useful to know whether a particular
miplevel is using HiZ or not.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

src/mesa/drivers/dri/i965/intel_mipmap_tree.c

@@ -1370,10 +1370,12 @@ intel_miptree_level_enable_hiz(struct brw_context *brw,
        * force the proper size alignments.
        */
       if (level > 0 && ((width & 7) || (height & 3))) {
+         DBG("mt %p level %d: HiZ DISABLED\n", mt, level);
          return false;
       }
    }
 
+   DBG("mt %p level %d: HiZ enabled\n", mt, level);
    mt->level[level].has_hiz = true;
    return true;
 }