intel: fix color/depth attachments size mismatch

The drawing rectangle should be the intersection of all color attachments and
the depth attachment.  Merge cmd_bind_rt() and cmd_bind_ds() into
cmd_bind_attachments() so that we can do that.

Move state emission to emit_rt() and emit_ds().
diff --git a/icd/intel/cmd.h b/icd/intel/cmd.h
index 81a38c8..af2023f 100644
--- a/icd/intel/cmd.h
+++ b/icd/intel/cmd.h
@@ -193,6 +193,8 @@
         XGL_UINT rt_count;
 
         const struct intel_ds_view *ds;
+
+        XGL_UINT width, height;
     } att;
 
     XGL_UINT draw_count;