[ARM] nommu: add stubs for ioremap and friends

nommu doesn't have any form of remapping support, so ioremap, etc
become stubs which just return the casted address, doing nothing
else.

Move ioport_map(), ioport_unmap(), pci_iomap(), pci_iounmap()
into a separate file which is always built.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/nommu.c

@@ -0,0 +1,30 @@
+/*
+ *  linux/arch/arm/mm/nommu.c
+ *
+ * ARM uCLinux supporting functions.
+ */
+#include <linux/module.h>
+
+#include <asm/io.h>
+#include <asm/page.h>
+
+void __iomem *__ioremap_pfn(unsigned long pfn, unsigned long offset,
+			    size_t size, unsigned long flags)
+{
+	if (pfn >= (0x100000000ULL >> PAGE_SHIFT))
+		return NULL;
+	return (void __iomem *) (offset + (pfn << PAGE_SHIFT));
+}
+EXPORT_SYMBOL(__ioremap_pfn);
+
+void __iomem *__ioremap(unsigned long phys_addr, size_t size,
+			unsigned long flags)
+{
+	return (void __iomem *)phys_addr;
+}
+EXPORT_SYMBOL(__ioremap);
+
+void __iounmap(void __iomem *addr)
+{
+}
+EXPORT_SYMBOL(__iounmap);