[Z80] more fixes to reset state, /IRQ and /NMI state should remain unchanged
[Z80] more fixes to reset state, /IRQ and /NMI state should remain unchanged

Oggom/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX,Oggom/Genesis-Plus-GX,DavidKnight247/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX,Oggom/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX,frangarcj/Genesis-Plus-GX,Oggom/Genesis-Plus-GX