* unbreak non-debug builds - don't default to debugging SCAN; that was
left-over from my testing.
* include opt_siba.h, now that it's generated as appropriate.
* stick the debug enum outside the debug block, just so it's there for
any code that wants to set siba_debug for some reason (like say,
my debugging muckup.)
* make DPRINTF() use __VA_ARGS__ for formatting too, so it correctly
handles printing w/ no args.
* Make DPRINTF() use device_printf().
Sponsored by: Palm Springs
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