drivers: usb: stm32 udc driver get the global otg interrupt

The global otg interrupt hs/fs is enabled by the udc_stm32
driver. Get it in the list of interrupts of the OTG node.
Use UDC_STM32_IRQ naming.

Signed-off-by: Francois Ramu <francois.ramu@st.com>
(cherry picked from commit 9ec7697b)