MIPS: Export copy_from_user_page() (needed by lustre)

ERROR: "copy_from_user_page" [drivers/staging/lustre/lustre/libcfs/libcfs.ko] undefined!
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/5808/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/mm/init.c

@@ -254,6 +254,7 @@ void copy_from_user_page(struct vm_area_struct *vma,
 			SetPageDcacheDirty(page);
 	}
 }
+EXPORT_SYMBOL_GPL(copy_from_user_page);
 
 void __init fixrange_init(unsigned long start, unsigned long end,
 	pgd_t *pgd_base)