i386: remove old IRQ balancing debug cruft

Dead or misnamed CONFIG_BALANCED_IRQ_DEBUG found by Robert P. J. Day.
It's not a Kconfig variable.

Since this debug code is ancient, I suggest to get rid of this
misleading CONFIG_ macro by deleting all of this debug code.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Robert P. J. Day" <rpjday@mindspring.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>