Increase MSI clock frequency when exiting deep sleep

This will optimize down the time it takes to restore the clock
settings when getting out of deep sleep.

If 48MHz is available let's use it, otherwise at least 4MHz should be
available for any MCU with MSI.

Author: LMESTM

targets/TARGET_STM/sleep.c

@@ -98,7 +98,11 @@ static void ForceOscOutofDeepSleep(void)
     RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
     RCC_OscInitStruct.MSIState = RCC_MSI_ON;
     RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
-    RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_4; // Intermediate freq, 1MHz range
+#if defined RCC_MSIRANGE_11
+    RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_11; // Highest freq, 48MHz range
+#else
+    RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_6; // 4MHz range
+#endif
     RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
 #else /* defined RCC_SYSCLKSOURCE_MSI */
     RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;