z80ctc: converted to use devcb2. nw.

Notes:
- for whatever reason the tlcs_z80 internal CTC fails to recognize/find its owner tag, 
does anyone know how to fix this? it's probably trivial, but I need an helping hand 
or pve500 cannot be launched anymore...
- @Haze: can you check your inder_sb.c code? your CTC interface was wrong,
judging from the comments in the source (the first cb was for the interrupt, and no 
callback was present by default for the ZC/TO3...) and I'm not sure what the code is 
intended to actually do