doc: reference: Add clock control API

Add the clock control API to the documentation reference.

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>

include/drivers/clock_control.h

@@ -6,9 +6,21 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+/**
+ * @file
+ * @brief Public Clock Control APIs
+ */
+
 #ifndef ZEPHYR_INCLUDE_DRIVERS_CLOCK_CONTROL_H_
 #define ZEPHYR_INCLUDE_DRIVERS_CLOCK_CONTROL_H_
 
+/**
+ * @brief Clock Control Interface
+ * @defgroup clock_control_interface Clock Control Interface
+ * @ingroup io_interfaces
+ * @{
+ */
+
 #include <zephyr/types.h>
 #include <stddef.h>
 #include <device.h>
@@ -229,4 +241,8 @@ static inline int clock_control_get_rate(struct device *dev,
 }
 #endif
 
+/**
+ * @}
+ */
+
 #endif /* ZEPHYR_INCLUDE_DRIVERS_CLOCK_CONTROL_H_ */