x86/ce4100: Fix reboot by forcing the reboot method to be KBD

The default reboot is via ACPI for this platform, and the CEFDK
bootloader actually supports this, but will issue a system power
off instead of a real reboot. Setting the reboot method to be
KBD instead of ACPI ensures proper system reboot.

Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
Cc: rui.zhang@intel.com
Cc: alan@linux.intel.com
Link: http://lkml.kernel.org/r/1351518020-25556-3-git-send-email-ffainelli@freebox.fr
Signed-off-by: Ingo Molnar <mingo@kernel.org>