openrisc: io: Add missing __iomem annotation to iounmap()

With C=1:

    drivers/soc/renesas/rmobile-sysc.c:330:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *addr @@     got void [noderef] __iomem *[assigned] base @@
    drivers/soc/renesas/rmobile-sysc.c:330:33: sparse:     expected void *addr
    drivers/soc/renesas/rmobile-sysc.c:330:33: sparse:     got void [noderef] __iomem *[assigned] base

Fix this by adding the missing __iomem annotation to iounmap().
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Stafford Horne <shorne@gmail.com>

arch/openrisc/include/asm/io.h

@@ -31,7 +31,7 @@
 void __iomem *ioremap(phys_addr_t offset, unsigned long size);
 
 #define iounmap iounmap
-extern void iounmap(void *addr);
+extern void iounmap(void __iomem *addr);
 
 #include <asm-generic/io.h>
 

arch/openrisc/mm/ioremap.c

@@ -77,7 +77,7 @@ void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size)
 }
 EXPORT_SYMBOL(ioremap);
 
-void iounmap(void *addr)
+void iounmap(void __iomem *addr)
 {
 	/* If the page is from the fixmap pool then we just clear out
 	 * the fixmap mapping.