INES Mapper 184

This mapper is for a few games which use the Sunsoft-1 mapper chip.

Fantasy Zone (J), despite using the Sunsoft-1 chip, is most readily emulated by Mapper 093 due to its board being wired differently than other mapper 184 boards.

Here is the documentation in disch's original style:

 Registers:
 --------------------------
   $6000-7FFF:  [.HHH .LLL]
     H = Selects 4k CHR @ $1000
     L = Selects 4k CHR @ $0000
 
 (The regs at $6000-7FFF means there can be no SRAM)