drivers: uart_mux: Fix documentation of uart_mux_recv()
The uart_mux_recv() documentation was wrong, the function parameters
were incorrectly documented.
@@ -26,9 +26,9 @@ int uart_mux_send(const struct device *uart, const uint8_t *buf, size_t size);
* @brief Receive unmuxed data.
*
* @param mux UART mux device structure.
- * @param uart Real UART device structure.
- * @param dlci_address DLCI id for the virtual muxing channel
- * @param timeout Amount of time to wait for the channel creation.
+ * @param dlci DLCI id for the muxing channel that should receive the data.
+ * @param data Received data (already unmuxed)
+ * @param len Length of the received data
*
* @retval >=0 No errors, number of bytes received
* @retval <0 Error
