hal_gpio: Remove misleading comments

Try to stop anyone else fixing a feature that is already fixed.

Author: andypugh

src/hal/drivers/hal_gpio.c

@@ -86,16 +86,16 @@ typedef struct{
 } hal_gpio_hal_t;
 
 /* flags are defined such:
- * bits 1 - 4 are gpiod flags
- * OPEN_DRAIN		= BIT(0) - not currently supported
- * OPEN_SOURCE		= BIT(1) - not currently supported
- * BIAS_DISABLE 	= BIT(2) - not currently supported
- * PULL_DOWN		= BIT(3) - not currently supported
- * PULL_UP		= BIT(4) - not currently supported
+ * bits 0 - 4 are gpiod flags
+ * OPEN_DRAIN		= BIT(0)
+ * OPEN_SOURCE		= BIT(1)
+ * BIAS_DISABLE 	= BIT(2)
+ * PULL_DOWN		= BIT(3)
+ * PULL_UP		= BIT(4)
  *
  * hal_gpio flags
  * INVERT 		= BIT(5)
- * RESET		= BIT(6) - not currently supported
+ * RESET		= BIT(6)
  */
 
 typedef struct {