ata.device modifications:
- replaced ata_RegisterBus 80wire BOOL with a bit flags field. I needed new flag to enable earlier interrupt handler setup to catch bus probe spurious interrupts (due to possible hardware bugs or IDE splitter) without hanging the machine.
- ata_HandleIRQ returns BOOL, lets interrupt handler to decide what to do if interrupt was spurious.
- Added DEVHEAD_VAL that is OR'd with ata_DevHead writes. Changed 0xA0 writes with 0x40 (spec says reserved bits should be written as zeros and bits 7 and 5 have been marked as reserved since ATA-2)
- added some more detection debugging.
- Put "USUALLY YOU'D WANT TO CHECK IF DISC IS PRESENT FIRST" inside D(). Message triggers under AOS.
git-svn-id: https://svn.aros.org/svn/aros/trunk/AROS@43983 fb15a70f-31f2-0310-bbcc-cdcc74a49acc