[PATCH] pause_on_oops command line option

Attempt to fix the problem wherein people's oops reports scroll off the screen
due to repeated oopsing or to oopses on other CPUs.

If this happens the user can reboot with the `pause_on_oops=<seconds>' option.
It will allow the first oopsing CPU to print an oops record just a single
time.  Second oopsing attempts, or oopses on other CPUs will cause those CPUs
to enter a tight loop until the specified number of seconds have elapsed.

The patch implements the infrastructure generically in the expectation that
architectures other than x86 will find it useful.

Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>