AP_Bootloader: support L496 MCUs

Tools/AP_Bootloader/bl_protocol.cpp

@@ -291,13 +291,18 @@ jump_to_app()
 #elif defined(STM32G4)
     rccDisableAPB1R1(~0);
     rccDisableAPB1R2(~0);
+#elif defined(STM32L4)
+    rccDisableAPB1R1(~0);
+    rccDisableAPB1R2(~0);
 #else
     rccDisableAPB1(~0);
 #endif
     rccDisableAPB2(~0);
 #if HAL_USE_SERIAL_USB == TRUE    
     rccResetOTG_FS();
+#if defined(rccResetOTG_HS)
     rccResetOTG_HS();
+#endif
 #endif
     
     // disable all interrupt sources

Tools/AP_Bootloader/board_types.txt

@@ -133,6 +133,7 @@ AP_HW_HEREID                         1043
 AP_HW_BirdCANdy                      1044
 AP_HW_SKYSTARSF405DJI                1045
 AP_HW_HITEC_AIRSPEED                 1046
+AP_HW_NucleoL496                     1047
 
 AP_HW_CUBEORANGE_PERIPH              1400
 AP_HW_CUBEBLACK_PERIPH               1401

Tools/AP_Bootloader/mcu_l4.h

@@ -0,0 +1,16 @@
+/*
+  MCU tables for STM32L4
+ */
+
+#if defined(STM32L4)
+
+#define STM32_UNKNOWN 0
+
+mcu_des_t mcu_descriptions[] = {
+    { STM32_UNKNOWN,     "STM32L4??",    '?'},
+};
+
+const mcu_rev_t silicon_revs[] = {
+};
+
+#endif // STM32L4

Tools/AP_Bootloader/support.cpp

@@ -17,6 +17,7 @@
 #include "mcu_f7.h"
 #include "mcu_h7.h"
 #include "mcu_g4.h"
+#include "mcu_l4.h"
 
 // optional uprintf() code for debug
 // #define BOOTLOADER_DEBUG SD1