panfrost: Fix logic ops on Bifrost
opaque should not be set when logicops are enabled, that needs blending even on Bifrost. Fixes is for when I believe the bug became possible to hit. The logical error is older.
Fixes Piglit logicop tests again.
Fixes: d849d977 ("panfrost: Avoid blend shader when not blending") Signed-off-by: Alyssa Rosenzweig alyssa@collabora.com