[radio] define `Radio::kInvalidRssi` constant (#8097)
This commit harmonizes the constant used to indicate an "Invalid RSSI
value". It defines `Radio::kInvalidRssi` which is then used in all
core modules replacing `OT_RADIO_INVALID_RSSI` and similar constants
in `SubMac/Mac`.
diff --git a/src/core/thread/link_quality.hpp b/src/core/thread/link_quality.hpp
index e919e3d..642dd58 100644
--- a/src/core/thread/link_quality.hpp
+++ b/src/core/thread/link_quality.hpp
@@ -125,13 +125,13 @@
/**
* This method adds a received signal strength (RSS) value to the average.
*
- * If @p aRss is OT_RADIO_RSSI_INVALID, it is ignored and error status kErrorInvalidArgs is returned.
+ * If @p aRss is `Radio::kInvalidRssi`, it is ignored and error status kErrorInvalidArgs is returned.
* The value of RSS is capped at 0dBm (i.e., for any given RSS value higher than 0dBm, 0dBm is used instead).
*
* @param[in] aRss Received signal strength value (in dBm) to be added to the average.
*
* @retval kErrorNone New RSS value added to average successfully.
- * @retval kErrorInvalidArgs Value of @p aRss is OT_RADIO_RSSI_INVALID.
+ * @retval kErrorInvalidArgs Value of @p aRss is `Radio::kInvalidRssi`.
*
*/
Error Add(int8_t aRss);
@@ -139,7 +139,7 @@
/**
* This method returns the current average signal strength value maintained by the averager.
*
- * @returns The current average value (in dBm) or OT_RADIO_RSSI_INVALID if no average is available.
+ * @returns The current average value (in dBm) or `Radio::kInvalidRssi` if no average is available.
*
*/
int8_t GetAverage(void) const;
@@ -317,7 +317,7 @@
/**
* This method returns the current average received signal strength value.
*
- * @returns The current average value or @c OT_RADIO_RSSI_INVALID if no average is available.
+ * @returns The current average value or `Radio::kInvalidRssi` if no average is available.
*
*/
int8_t GetAverageRss(void) const { return mRssAverager.GetAverage(); }