panfrost: ci: Exclude two more flip-flop from results

These three tests pass on RK3399, but fail on RK3288:

dEQP-GLES2.functional.shaders.matrix.div.const_lowp_mat2_mat2_vertex
dEQP-GLES2.functional.shaders.operator.unary_operator.pre_increment_effect.highp_ivec4_vertex
dEQP-GLES2.functional.shaders.texture_functions.vertex.texture2dprojlod_vec3

They reliably pass when run individually, but reliably fail when run in
a full CI run.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
1 file changed