GCS_MAVLink: import LANDING_TARGET from upstream

libraries/GCS_MAVLink/message_definitions/common.xml

@@ -2629,6 +2629,14 @@
             <field type="uint16_t" name="product_id">ID of the product</field>
             <field type="uint64_t" name="uid">UID if provided by hardware</field>
         </message>
+        <message id="149" name="LANDING_TARGET">
+            <description>The location of a landing area captured from a downward facing camera</description>
+            <field type="uint8_t" name="target_num">The ID of the target if multiple targets are present</field>
+            <field type="uint8_t" name="frame">MAV_FRAME enum specifying the whether the following feilds are earth-frame, body-frame, etc.</field>
+            <field type="float" name="angle_x">X-axis angular offset (in radians) of the target from the center of the image</field>
+            <field type="float" name="angle_y">Y-axis angular offset (in radians) of the target from the center of the image</field>
+            <field type="float" name="distance">Distance to the target from the vehicle in meters</field>
+        </message>
         <!-- MESSAGE IDs 180 - 240: Space for custom messages in individual projectname_messages.xml files -->
         <message id="241" name="VIBRATION">
             <description>Vibration levels and accelerometer clipping</description>