OPENMV4: Switch USB clock source to HSI48.
#define OMV_OSC_PLL3FRAC (0)
// Clock Sources
-#define OMV_OSC_USB_CLKSOURCE RCC_USBCLKSOURCE_PLL
+#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
