arm26: remove it again

A tiny vestige of arm26 has appeared: remove it again.

(akpm: someone (tm) needs to remove include/asm-arm26/ too)
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/asm-arm26/irq_regs.h

-#include <asm-generic/irq_regs.h>