PORTENTA: Set RNG clock source.
// Clock Sources
#define OMV_OSC_USB_CLKSOURCE RCC_USBCLKSOURCE_HSI48
+#define OMV_OSC_RNG_CLKSOURCE RCC_RNGCLKSOURCE_HSI48
#define OMV_OSC_ADC_CLKSOURCE RCC_ADCCLKSOURCE_PLL3
#define OMV_OSC_SPI123_CLKSOURCE RCC_SPI123CLKSOURCE_PLL3
