amd64/89503: Cant Boot Installation Disk

[Antoine Pelisse]

There is a fix for this bug and it's documented by atkbd(5) in the Driver
Flags section:
     bit 3 (NO_PROBE_TEST)
           When this option is given, the atkbd driver will not test the
key-
           board port during the probe routine.  Some machines hang during
           boot when this test is performed.
However, this doesn't work on my AMD64 laptop computer and I'm currently
trying to pinpoint the actual problem. (seems to be related to the keyboard
nonetheless)