usb: add missing stdint.h includes

Some class headers were not including stdint.h themselves, despite
relying on those types, and relying on them already being included
earlier elsewhere.  Consistently include stdint.h where it's used.

Fixes: https://github.com/libopencm3/libopencm3/issues/1471
Signed-off-by: Karl Palsson <karlp@tweak.au>

include/libopencm3/usb/dfu.h

@@ -38,6 +38,8 @@ LGPL License Terms @ref lgpl_license
 #ifndef __DFU_H
 #define __DFU_H
 
+#include <stdint.h>
+
 #define USB_CLASS_DFU 0xFE
 
 enum dfu_req {

include/libopencm3/usb/msc.h

@@ -40,6 +40,8 @@ LGPL License Terms @ref lgpl_license
 #ifndef __MSC_H
 #define __MSC_H
 
+#include <stdint.h>
+
 typedef struct _usbd_mass_storage usbd_mass_storage;
 
 /* Definitions of Mass Storage Class from: