drivers: udc: stm32: update `STM32_CLOCK_CHECK` definition

Introduce `UDC_STM32_CLOCK_CHECK` Kconfig option since
`USB_DC_STM32_CLOCK_CHECK` was intended for use with `usb_dc_stm32.c`,
which is mutually exclusive with `udc_stm32.c`.

Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>