microblaze: Fix coding style issues

Fix coding style issues reported by checkpatch.pl.

Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/pci/iomap.c b/arch/microblaze/pci/iomap.c
index b07abba..94149f5 100644
--- a/arch/microblaze/pci/iomap.c
+++ b/arch/microblaze/pci/iomap.c
@@ -7,7 +7,7 @@
 #include <linux/pci.h>
 #include <linux/mm.h>
 #include <linux/export.h>
-#include <asm/io.h>
+#include <linux/io.h>
 #include <asm/pci-bridge.h>
 
 void pci_iounmap(struct pci_dev *dev, void __iomem *addr)