Why:
* Doing "clear_halt" is normally the right thing to do on startup.
* The original observed problem is better fixed via USB bios settings.
* Defaulting to no "clear_halt" cause more problems on other platform
combinations (hardware/kernel).
The change:
* We now reverted to do "clear_halt" by default.
* The XTALK_OPTIONS may now contain either "use-clear-halt" (the default)
or "no-use-clear-halt" to override for debugging/testing.
Original commit: ca7c04e9cb
Signed-off-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
9aee76a3a5