AP_Motors: allow AP_SCRIPTING_ENABLED to come from hwdef files

libraries/AP_Motors/AP_MotorsMatrix_6DoF_Scripting.cpp

@@ -13,6 +13,8 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <AP_Scripting/AP_Scripting_config.h>
+
 #if AP_SCRIPTING_ENABLED
 
 #include <AP_HAL/AP_HAL.h>

libraries/AP_Motors/AP_MotorsMatrix_Scripting_Dynamic.cpp

@@ -12,6 +12,9 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+
+#include <AP_Scripting/AP_Scripting_config.h>
+
 #if AP_SCRIPTING_ENABLED
 
 // This allows motor roll, pitch, yaw and throttle factors to be changed in flight, allowing vehicle geometry to be changed