x86: Cleanup hw_nmi.c cruft

x86: Cleanup hw_nmi.c cruft

The design of the hardlockup watchdog has changed and cruft was left
behind in the hw_nmi.c file.  Just remove the code that isn't used
anymore.

Signed-off-by: Don Zickus <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Cyrill Gorcunov <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: Randy Dunlap <[email protected]>
LKML-Reference: <1273266711[email protected]>
Signed-off-by: Frederic Weisbecker <[email protected]>