* Move to more standardized functions matching AHCI spec
* Don't perform unnecessary double port resets
* Begin implementing a software reset to try first per spec.
Software reset needs more work, falls through to port reset
for the moment which is stable.
* Don't duplicate ATA defines, use what we already provide.
* Tested working on VirtualBox 1-16 AHCI ports, Intel C200,
and AMD FCH.
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