Remove unnecessary args from GPIO functions

Now that gpio_init() and read_gpios() doesn't use
D-Bus, they don't need the D-Bus connection parameter.

Change-Id: Id7f3ee6547bed7c0c0eed5d75cba2d6ff239d0fa
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/libopenbmc_intf/gpio.h b/libopenbmc_intf/gpio.h
index a7ab8e2..dc439c8 100644
--- a/libopenbmc_intf/gpio.h
+++ b/libopenbmc_intf/gpio.h
@@ -24,7 +24,7 @@
 #define GPIO_WRITE_ERROR  0x10
 #define GPIO_LOOKUP_ERROR 0x20
 
-int gpio_init(GDBusConnection*, GPIO*);
+int gpio_init(GPIO*);
 void gpio_close(GPIO*);
 int  gpio_open(GPIO*);
 int gpio_open_interrupt(GPIO*, GIOFunc, gpointer);