mm,x86: fix kmap_atomic_push vs ioremap_32.c

It appears i386 uses kmap_atomic infrastructure regardless of
CONFIG_HIGHMEM which results in a compile error when highmem is disabled.

Cure this by providing the needed few bits for both CONFIG_HIGHMEM and
CONFIG_X86_32.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/highmem.c b/mm/highmem.c
index 781e754..693394d 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -29,6 +29,11 @@
 #include <linux/kgdb.h>
 #include <asm/tlbflush.h>
 
+
+#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+DEFINE_PER_CPU(int, __kmap_atomic_idx);
+#endif
+
 /*
  * Virtual_count is not a pure "count".
  *  0 means that it is not mapped, and has not been mapped
@@ -43,7 +48,6 @@
 EXPORT_SYMBOL(totalhigh_pages);
 
 
-DEFINE_PER_CPU(int, __kmap_atomic_idx);
 EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
 
 unsigned int nr_free_highpages (void)