AP_HAL_SITL: add get_storage_ptr method

libraries/AP_HAL_SITL/Storage.cpp

@@ -388,4 +388,15 @@ bool Storage::healthy(void)
     return AP_HAL::millis() - _last_empty_ms < 2000;
 }
 
-
+/*
+  get storage size and ptr
+ */
+bool Storage::get_storage_ptr(void *&ptr, size_t &size)
+{
+    if (_initialisedType==StorageBackend::None) {
+        return false;
+    }
+    ptr = _buffer;
+    size = sizeof(_buffer);
+    return true;
+}

libraries/AP_HAL_SITL/Storage.h

@@ -28,6 +28,7 @@ public:
     void init() override {}
     void read_block(void *dst, uint16_t src, size_t n) override;
     void write_block(uint16_t dst, const void* src, size_t n) override;
+    bool get_storage_ptr(void *&ptr, size_t &size) override;
 
     void _timer_tick(void) override;
     bool healthy(void) override;