drivers: usb: udc: stm32: turn EP0 max packet size into a constant

The EP0 max packet size was de facto a constant because its value was the
same regardless of which USB IP was in use. However, it was stored as part
of the instance configuration anyways which is wasteful and slower.

Create new "UDC_STM32_EP0_MAX_PACKET_SIZE" driver-level constant with which
all usage of the per-instance configuration field is replaced.

Signed-off-by: Mathieu Choplain <mathieu.choplain-ext@st.com>
1 file changed