freedreno/ir3: Disable sin/cos range reduction for mediump.
robclark noted that the blob wasn't doing range reduction in the mediump case, and I confirmed it on dEQP-GLES3.functional.shaders.operator.angle_and_trigonometry.sin.mediump_float_fragment vs dEQP-GLES3.functional.shaders.operator.angle_and_trigonometry.sin.highp_float_fragment.