Summary

• Implement SMI I/O trap on the SiS 496/497 fixing APM on the Lucky Star LS-486E
• SMIs fired by changing SiS 558x register 93h are not affected by the ACPI config bits, fixes SMM/APM on both machines

Checklist

• Closes #xxx
• I have tested my changes locally and validated that the functionality works as intended
• I have discussed this with core contributors already
• This pull request requires changes to the ROM set
  • I have opened a roms pull request - https://github.com/86Box/roms/pull/changeme/
• This pull request requires changes to the asset set
  • I have opened an assets pull request - https://github.com/86Box/assets/pull/changeme/

References

Provide links to datasheets or other documentation that helped you implement this pull request.

• SiS 496/497 datasheet: https://theretroweb.com/chipset/documentation/4967-2-649447c6a7c50999895435.pdf
• SiS 558x datasheet: https://theretroweb.com/chipset/documentation/5581-2-64a8a210858dc799696886.pdf