Initial OTG support for STM32H7 and some minor improvements
arch/arm/src/stm32h7/stm32h7x3xx_rcc.c: add support for HSI48 clock
configs/nucleo-f207zg: add support for USB and initialize CDCACM if configured
configs/nucleo-h743zi: add support for USB and initialize CDCACM if configured
drivers/usbdev/Kconfig: fix type for USBDEV_TRACE_INITIALIDSET
configs/teensy-3.x/usbnsh/defconfig: update config according to change in USBDEV_TRACE_INITIALIDSET
Approved-by: Gregory Nutt <gnutt@nuttx.org>