freedreno/a2xx: Fix compiler warning in disasm.
warning: converting a packed ‘instr_cf_t’ {aka ‘union ’} pointer (alignment 1) to a ‘uint16_t’ {aka ‘short unsigned int’} pointer (alignment 2) may result in an unaligned pointer value [-Waddress-of-packed-member]
We may know that we'll only ever have aligned instr_cf_ts, but gcc doesn't.