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
diff --git a/include/drivers/usb_device.h b/include/drivers/usb_device.h
index 8fdb6ae..d4c491c 100644
--- a/include/drivers/usb_device.h
+++ b/include/drivers/usb_device.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, STMicroelectronics - All Rights Reserved
+ * Copyright (c) 2021-2024, STMicroelectronics - All Rights Reserved
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,6 +7,7 @@
 #ifndef USB_DEVICE_H
 #define USB_DEVICE_H
 
+#include <stdbool.h>
 #include <stdint.h>
 
 #include <lib/utils_def.h>