The fixing of the watchdog driver makes it generate a NMI so the reboot_fixup
can no longer be called from NMI context, instead, override the machine_retart
callback with our southrbridge reboot mechanism. Patch by Bernhard Loos.
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@19977 3c298f89-4303-0410-b956-a3cf2f4a3e73