gpio-ml-ioh: cleanup __iomem annotation usage

The __iomem annotation is to be used together with pointers used
in iowrite32() but not for pointers returned by kzalloc().
For more details see [1] and [2].

This patch will remove the following sparse warning (i.e. when
copiling with "make C=1"):
 * warning: incorrect type in assignment (different address spaces)

References:
[1] A new I/O memory access mechanism (Sep 15, 2004)
    http://lwn.net/Articles/102232/

[2] Being more anal about iospace accesses (Sep 15, 2004)
    http://lwn.net/Articles/102240/Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/gpio/gpio-ml-ioh.c

@@ -248,7 +248,7 @@ static void ioh_gpio_setup(struct ioh_gpio *chip, int num_port)
 static int ioh_irq_type(struct irq_data *d, unsigned int type)
 {
 	u32 im;
-	u32 *im_reg;
+	void __iomem *im_reg;
 	u32 ien;
 	u32 im_pos;
 	int ch;
@@ -412,7 +412,7 @@ static int __devinit ioh_gpio_probe(struct pci_dev *pdev,
 	int i, j;
 	struct ioh_gpio *chip;
 	void __iomem *base;
-	void __iomem *chip_save;
+	void *chip_save;
 	int irq_base;
 
 	ret = pci_enable_device(pdev);
@@ -521,7 +521,7 @@ static void __devexit ioh_gpio_remove(struct pci_dev *pdev)
 	int err;
 	int i;
 	struct ioh_gpio *chip = pci_get_drvdata(pdev);
-	void __iomem *chip_save;
+	void *chip_save;
 
 	chip_save = chip;