freedreno/ir3: sync instr/disasm and add ldib encoding

freedreno/ir3: sync instr/disasm and add ldib encoding

Resync disasm and instr header from envytools, and add ldib encoding.
This replaces an opcode from a3xx which was never seen in practice,
since that seemed easier than dealing with the same opc # meaning a
different thing on a6xx.  (Not really sure if 'sti' was actually a
real thing, I think it was only seen in fuzzing.)

Signed-off-by: Rob Clark <robdclark@gmail.com>