mw8080bw: 280zzzap netlist audio (#6760)

* mw8080bw: update 280zzzap audio API in preparation for netlist audio

This is only API changes, following the pattern used by cuavas within the
past year to update other games in mw8080bw.

* mw8080bw: new netlist audio implementation for 280zzzap

New netlist-based audio implementation for 280zzzap (280-ZZZAP, 1976),
derived from Midway game logic board schematic. The sound generally
matches that heard in videos of the machine, though the real machine
seems to have more bass and less treble. This may be a cabinet effect
or something else, such as a difference in component values.

Due to the number of complex components being emulated and the nature
of the circuits, this netlist adds a lot of overhead, but it's still
fast enough to run at greater than real speed on modern hardware.

With minor changes, this implementation should also support lagunar
(Laguna Racer, 1977); with somewhat more substantial changes, it
would also support sspeedr (Super Speed Race, 1979). Both of these
games use sound circuits based on those for 280-ZZZAP.

scripts/target/mame/arcade.lua

@@ -2735,6 +2735,8 @@ files {
 	MAME_DIR .. "src/mame/audio/mw8080bw.h",
 	MAME_DIR .. "src/mame/audio/nl_gunfight.cpp",
 	MAME_DIR .. "src/mame/audio/nl_gunfight.h",
+	MAME_DIR .. "src/mame/audio/nl_280zzzap.cpp",
+	MAME_DIR .. "src/mame/audio/nl_280zzzap.h",
 	MAME_DIR .. "src/mame/video/mw8080bw.cpp",
 	MAME_DIR .. "src/mame/drivers/rotaryf.cpp",
 }

scripts/target/mame/nl.lua

@@ -193,6 +193,8 @@ files{
   MAME_DIR .. "src/mame/video/mw8080bw.cpp",
 	MAME_DIR .. "src/mame/audio/nl_gunfight.cpp",
 	MAME_DIR .. "src/mame/audio/nl_gunfight.h",
+	MAME_DIR .. "src/mame/audio/nl_280zzzap.cpp",
+	MAME_DIR .. "src/mame/audio/nl_280zzzap.h",
 
 	MAME_DIR .. "src/mame/audio/cheekyms.cpp",
 	MAME_DIR .. "src/mame/audio/cheekyms.h",