i2c: ismt: mark register space with __iomem

This fixes the code to suppress sparse warnings like:

drivers/i2c/busses/i2c-ismt.c:725:36: warning: incorrect type in argument 2 (different address spaces)
drivers/i2c/busses/i2c-ismt.c:725:36:    expected void volatile [noderef] <asn:2>*addr
drivers/i2c/busses/i2c-ismt.c:725:36:    got void *

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-ismt.c

@@ -165,7 +165,7 @@ struct ismt_desc {
 
 struct ismt_priv {
 	struct i2c_adapter adapter;
-	void *smba;				/* PCI BAR */
+	void __iomem *smba;			/* PCI BAR */
 	struct pci_dev *pci_dev;
 	struct ismt_desc *hw;			/* descriptor virt base addr */
 	dma_addr_t io_rng_dma;			/* descriptor HW base addr */