drivers: usb: device: stm32: Configure USB Prescaler for F103

- If the HAL headers expose the USBPRE flag, then we're probably
  dealing with a F103 - using the same fundamental logic as the
  code for the OTG models, set-up the USB Prescaler correctly.

- Fixes #47146

Signed-off-by: Chris Collins <chris@realsimgear.com>