powerpc/mpic_msgr: Add missing includes

Add several #includes that mpic_msgr relies on being pulled implicitly,
which only happens on certain configs.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Meador Inge <meador_inge@mentor.com>
Cc: Jia Hongtao <B38951@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/mpic_msgr.h b/arch/powerpc/include/asm/mpic_msgr.h
index 326d33c..d4f471f 100644
--- a/arch/powerpc/include/asm/mpic_msgr.h
+++ b/arch/powerpc/include/asm/mpic_msgr.h
@@ -14,6 +14,7 @@
 #include <linux/types.h>
 #include <linux/spinlock.h>
 #include <asm/smp.h>
+#include <asm/io.h>
 
 struct mpic_msgr {
 	u32 __iomem *base;