parisc: Document the fw_cfg opt/pdc_debug option

Enable firmware debug info at startup with this option:
    -fw_cfg pdc_debug,string=<val>
<val> is an integer with this bitmask:
DEBUG_PDC       0x0001, enables debug info for PDC calls
DEBUG_IODC      0x0002, enables debug info for IODC calls

Signed-off-by: Helge Deller <deller@gmx.de>
1 file changed