STM32WB: Only configure default peripherals in SetSysClock

Typically the RTC clock is configured by RTC driver itself.

RNG on the other hand is shared with M0+ core and it is expected that
M4 turns it on at boot time.

Author: LMESTM

targets/TARGET_STM/TARGET_STM32WB/TARGET_STM32WB55xG/TARGET_NUCLEO_WB55RG/system_clock.c

@@ -177,12 +177,10 @@ uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
   __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
   /** Initializes the CPU, AHB and APB busses clocks
   */
-  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_LSI1
-                              |RCC_OSCILLATORTYPE_HSE;
+  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_HSE;
   RCC_OscInitStruct.HSEState = RCC_HSE_ON;
   RCC_OscInitStruct.HSIState = RCC_HSI_ON;
   RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
-  RCC_OscInitStruct.LSIState = RCC_LSI_ON;
   RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
   if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
   {
@@ -206,13 +204,7 @@ uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
   }
   /** Initializes the peripherals clocks
   */
-  PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_SMPS|RCC_PERIPHCLK_RFWAKEUP
-                              |RCC_PERIPHCLK_RTC|RCC_PERIPHCLK_USART1
-                              |RCC_PERIPHCLK_LPUART1;
-  PeriphClkInitStruct.Usart1ClockSelection = RCC_USART1CLKSOURCE_PCLK2;
-  PeriphClkInitStruct.Lpuart1ClockSelection = RCC_LPUART1CLKSOURCE_PCLK1;
-  PeriphClkInitStruct.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;
-  PeriphClkInitStruct.RFWakeUpClockSelection = RCC_RFWKPCLKSOURCE_LSI;
+  PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_SMPS;
   PeriphClkInitStruct.SmpsClockSelection = RCC_SMPSCLKSOURCE_HSE;
   PeriphClkInitStruct.SmpsDivSelection = RCC_SMPSCLKDIV_RANGE0;
 
@@ -226,6 +218,13 @@ uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
    */
   LL_RCC_SetClkAfterWakeFromStop(LL_RCC_STOP_WAKEUPCLOCK_HSI);
 
+  /**
+   * Set RNG on HSI48
+   */
+  LL_RCC_HSI48_Enable();
+  while(!LL_RCC_HSI48_IsReady());
+  LL_RCC_SetCLK48ClockSource(LL_RCC_CLK48_CLKSOURCE_HSI48);
+
   return 1;
 }