stm32: usb: Drivers clean up

[erwango]

Is your enhancement proposal related to a problem? Please describe.
STM32 USB drivers have been implemented and maintained w/o using dts information sufficiently.
They have became hard to read and maintain.

Describe the solution you'd like
Review driver implementation to maximize usage of dt information. Ultimately, driver should be fully instantiable (at least for usb next version).
There are multiple steps from low hanging fruits from bindings overhaul.
#71248 should be part of this effort.

Example of low hanging fruit:

#if defined(USB)
	priv->pcd.Instance = DT_INST_REG_ADDR(0);
#elif defined(USB_DRD_FS)
	priv->pcd.Instance = USB_DRD_FS;
#elif defined(USB_OTG_FS) || defined(USB_OTG_HS)
	priv->pcd.Init.speed = usb_dc_stm32_get_maximum_speed();
#if DT_HAS_COMPAT_STATUS_OKAY(st_stm32_otghs)
	priv->pcd.Instance = USB_OTG_HS;
#else
	priv->pcd.Instance = USB_OTG_FS;
#endif
#endif /* USB */

could be replaced by

	priv->pcd.Instance = (USB_OTG_GlobalTypeDef *)DT_INST_REG_ADDR(0);

#if defined(USB_OTG_FS) || defined(USB_OTG_HS)
	priv->pcd.Init.speed = usb_dc_stm32_get_maximum_speed();
#endif

Side notes:
Implementation should get rid of STM32Cube defines, such as:
USB, USB_DRD_FS