clock_control: int is returned on enum return value

[alexanderwachter]

Describe the bug
When using clock_control.h in an app, it does not compile due to warnings.
The return value of the function in an enum, but in case the device is not ready, a posix error code is returned.

static inline enum clock_control_status clock_control_get_status(const struct device *dev,
								 clock_control_subsys_t sys)
{
	const struct clock_control_driver_api *api =
		(const struct clock_control_driver_api *)dev->api;

	if (!api->get_status) {
		return CLOCK_CONTROL_STATUS_UNKNOWN;
	}

	if (!device_is_ready(dev)) {
		return -ENODEV;
	}

	return api->get_status(dev, sys);
}

To Reproduce
Compile a C++ app that includes clock_control.h

Expected behavior
Only return values from the enum

Impact
APP does not compile

Logs and console output

zephyr/include/drivers/clock_control.h:193:11: error: invalid conversion from 'int' to 'clock_control_status' [-fpermissive]
  193 |   return -ENODEV;
      |           ^~~~~~
      |           |
      |           int

[alexanderwachter]

PR: #32386