This stores the constant coefficients deinterleaved, so that they can be
loaded directly with NF=0. Unfortunately, we cannot optimise loading the
input, due to insufficient memory alignment (not 32-bit).

Before:
g722_apply_qmf_c:       82.5
g722_apply_qmf_rvv_i32: 78.2

After:
g722_apply_qmf_c:       82.5
g722_apply_qmf_rvv_i32: 65.2