anv: Implement a depth stall restriction on gen7

Fixes around 60 Vulkan CTS tests on Haswell

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Cc: "13.0" <mesa-stable@lists.freedesktop.org>

src/intel/vulkan/genX_blorp_exec.c

@@ -152,6 +152,8 @@ genX(blorp_exec)(struct blorp_batch *batch,
 
    genX(flush_pipeline_select_3d)(cmd_buffer);
 
+   genX(cmd_buffer_emit_gen7_depth_flush)(cmd_buffer);
+
    blorp_exec(batch, params);
 
    cmd_buffer->state.vb_dirty = ~0;