arch/alpha: remove duplicate includes

Signed-off-by: Lucas Woods <woodzy@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/alpha/kernel/setup.c

@@ -58,7 +58,6 @@ static struct notifier_block alpha_panic_block = {
 #include <asm/system.h>
 #include <asm/hwrpb.h>
 #include <asm/dma.h>
-#include <asm/io.h>
 #include <asm/mmu_context.h>
 #include <asm/console.h>