ARM: ux500: use __iomem pointers for MMIO

In the earlier sweeping changes, the ux500 uncompress.h file was missed
because other problems were hiding this one.

Without this patch, building u8500_defconfig results in:

In file included from arch/arm/boot/compressed/misc.c:33:0:
arch/arm/mach-ux500/include/mach/uncompress.h: In function 'putc':
arch/arm/mach-ux500/include/mach/uncompress.h:32:2: warning: passing argument 1 of '__raw_readb' makes pointer from integer without a cast [enabled by default]
arch/arm/include/asm/io.h:95:89: note: expected 'const volatile void *' but argument is of type 'u32'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Linus Walleij <linus.walleij@linaro.org>

arch/arm/mach-ux500/include/mach/uncompress.h

@@ -24,7 +24,7 @@
 #include <linux/amba/serial.h>
 #include <mach/hardware.h>
 
-u32 ux500_uart_base;
+void __iomem *ux500_uart_base;
 
 static void putc(const char c)
 {
@@ -51,7 +51,7 @@ static void flush(void)
 static inline void arch_decomp_setup(void)
 {
 	/* Use machine_is_foo() macro if you need to switch base someday */
-	ux500_uart_base = U8500_UART2_BASE;
+	ux500_uart_base = (void __iomem *)U8500_UART2_BASE;
 }
 
 #define arch_decomp_wdog() /* nothing to do here */