Update Musashi to fix PEA cycle count
Update Musashi to fix PEA cycle count

Now libmusashi.a includes the latest PR, which fixes PEA cycle count
for the AI addressing mode, see
https://github.com/kstenerud/Musashi/pull/18

All qc-tests now pass (1466 tests in about 37 minutes)

marhel/r68k,marhel/r68k,emoon/r68k,emoon/r68k