fix(usb): add missing include

When trying to compile USB stack for STM32MP2, the following warning
happens:
In file included from plat/st/stm32mp2/stm32mp2_usb_dfu.c:7:
include/drivers/usb_device.h:193:9: error: unknown type name 'bool'
  193 |         bool is_in;

Correct it by adding: #include <stdbool.h>

Signed-off-by: Yann Gautier <yann.gautier@st.com>
Change-Id: If17e4e269fcdc885e42f5fcad9cfb763829786e4
1 file changed