[ARM] Fix nommu build

Fix warnings and errors in arch/arm/mm for nommu build.
Remove commented out function prototype in pgtable-nommu.h

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c
index d0e6642..05818fc 100644
--- a/arch/arm/mm/nommu.c
+++ b/arch/arm/mm/nommu.c
@@ -6,10 +6,12 @@
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
+#include <linux/bootmem.h>
 
 #include <asm/cacheflush.h>
 #include <asm/io.h>
 #include <asm/page.h>
+#include <asm/mach/arch.h>
 
 #include "mm.h"
 
@@ -76,7 +78,7 @@
 }
 EXPORT_SYMBOL(__ioremap);
 
-void __iounmap(void __iomem *addr)
+void __iounmap(volatile void __iomem *addr)
 {
 }
 EXPORT_SYMBOL(__iounmap);