[non-normative] Change CfL lossess if to match Spec

This change does not impact the behavior of the encoder, it simply
changes the if statement to match what is proposed in

https://github.com/AOMediaCodec/av1-spec/commit/6642ce69ba2599a45ad6338cf492b12e1c31dc7c#diff-9cd50b4cca449cb68799aca38a5ae21cL1877

Change-Id: I10b2bce152c15686d077e1232832b9e6bcbe3399
diff --git a/av1/common/cfl.h b/av1/common/cfl.h
index e7d3542..b737ef7 100644
--- a/av1/common/cfl.h
+++ b/av1/common/cfl.h
@@ -23,8 +23,7 @@
     // transform size.
     const int plane_bsize =
         get_plane_block_size(bsize, &xd->plane[AOM_PLANE_U]);
-    return (CFL_ALLOWED_TYPE)(block_size_wide[plane_bsize] == 4 &&
-                              block_size_high[plane_bsize] == 4);
+    return (CFL_ALLOWED_TYPE)(plane_bsize == BLOCK_4X4);
   }
   // Spec: CfL is available to luma partitions lesser than or equal to 32x32
   return (CFL_ALLOWED_TYPE)(block_size_wide[bsize] <= 32 &&