boards: cxd56xx: Set the pin number to the argument of gpio handler

Make it easy to get the pin number on GPIO interrupt handler.

boards/arm/cxd56xx/spresense/src/cxd56_gpioif.c

@@ -188,7 +188,8 @@ int board_gpio_intconfig(uint32_t pin, int mode, bool filter, xcpt_t isr)
       gpiocfg |= GPIOINT_NOISE_FILTER_ENABLE;
     }
 
-  ret = cxd56_gpioint_config(pin, gpiocfg, isr, NULL);
+  ret = cxd56_gpioint_config(pin, gpiocfg, isr, (void *)pin);
+
   return ret;
 #else
   return -ENOTSUP;