Summary

1. Too many soft resets should not reset the SCSI layer, fixes CD Audio on the 53c90a MCA controller used by guests.
2. Implemented preliminary MDL S/G mode for the PCSCSI side.
3. The underflow DMA function is no longer needed as it now SCSI transfers on the 53c90a MCA controller works properly.
4. Minor corrections to the PCI side (mainly the revision).
5. The DMA 86c01 side of the MCA 53c90a controller is more polished now, should fix some more bugs.

Checklist

• Closes #xxx
• 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/

References

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