microblaze: Do not use module.h in files which are not modules

Based on the patch:
"lib: reduce the use of module.h wherever possible"
(sha1: 8bc3bcc93a)
fix all microblaze files which are not modules.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/microblaze/mm/highmem.c

@@ -20,8 +20,8 @@
  * highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
  */
 
+#include <linux/export.h>
 #include <linux/highmem.h>
-#include <linux/module.h>
 
 /*
  * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap