AP_Bootloader: support STM32F303 MCU

Tools/AP_Bootloader/mcu_f3.h

@@ -0,0 +1,15 @@
+/*
+  support tables for STM32F3
+ */
+
+#if defined(STM32F3)
+#define STM32_UNKNOWN	0
+
+const mcu_des_t mcu_descriptions[] = {
+    { STM32_UNKNOWN,	"STM32F3xx",    '?'},
+};
+
+const mcu_rev_t silicon_revs[] = {
+};
+
+#endif // STM32F3

Tools/AP_Bootloader/support.cpp

@@ -11,6 +11,7 @@
 #include <AP_HAL_ChibiOS/hwdef/common/stm32_util.h>
 #include "support.h"
 #include "mcu_f1.h"
+#include "mcu_f3.h"
 #include "mcu_f4.h"
 #include "mcu_f7.h"
 #include "mcu_h7.h"