microblaze: Use proper casting for inb/inw/inl in io.h

We are going to move to asm-generic/io.h but
let's fix compilation warnings first for 3.10.

Warning message:
arch/microblaze/include/asm/io.h:126:26: warning: cast to
 pointer from integer of different size [-Wint-to-pointer-cast]
 #define inb(port)  readb((u8 *)((port)))
...
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/microblaze/include/asm/io.h

@@ -123,11 +123,11 @@ static inline void writel(unsigned int v, volatile void __iomem *addr)
  * inb_p/inw_p/...
  * The macros don't do byte-swapping.
  */
-#define inb(port)		readb((u8 *)((port)))
+#define inb(port)		readb((u8 *)((unsigned long)(port)))
 #define outb(val, port)		writeb((val), (u8 *)((unsigned long)(port)))
-#define inw(port)		readw((u16 *)((port)))
+#define inw(port)		readw((u16 *)((unsigned long)(port)))
 #define outw(val, port)		writew((val), (u16 *)((unsigned long)(port)))
-#define inl(port)		readl((u32 *)((port)))
+#define inl(port)		readl((u32 *)((unsigned long)(port)))
 #define outl(val, port)		writel((val), (u32 *)((unsigned long)(port)))
 
 #define inb_p(port)		inb((port))