mfd: rdc321x: Fix off-by-one for ngpio setting

The valid gpio is GPIO0 ~ GPIO58, so ngpio should be 59.
This patch also renames RDC321X_MAX_GPIO to RDC321X_NUM_GPIO because it
actually means the number of available GPIOs.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/include/linux/mfd/rdc321x.h b/include/linux/mfd/rdc321x.h
index 4bdf19c..442743a 100644
--- a/include/linux/mfd/rdc321x.h
+++ b/include/linux/mfd/rdc321x.h
@@ -12,7 +12,7 @@
 #define RDC321X_GPIO_CTRL_REG2	0x84
 #define RDC321X_GPIO_DATA_REG2	0x88
 
-#define RDC321X_MAX_GPIO	58
+#define RDC321X_NUM_GPIO	59
 
 struct rdc321x_gpio_pdata {
 	struct pci_dev *sb_pdev;