turnip: fix SP_HS_WAVE_INPUT_SIZE value

It appears that storage for varyings in a wave has an upper limit of wavesize * max_a831 where max_a831 is 64. Exceeding the limit seam to force gpu to reduce primitives processed per wave, at least calculations make sense with such interpretation.

With blob SP_HS_WAVE_INPUT_SIZE never exceeds 64 and setting it to 65 in freedreno leads to a hang.

Copied from the commit to freedreno e5499ca2