waf: keep EKF2 enabled in SITL

just because we don't compile this in doesn't mean we shouldn't continue to test it

Tools/ardupilotwaf/boards.py

@@ -654,6 +654,12 @@ class sitl(Board):
         cfg.define('AP_NOTIFY_LP5562_BUS', 2)
         cfg.define('AP_NOTIFY_LP5562_ADDR', 0x30)
 
+        try:
+            env.CXXFLAGS.remove('-DHAL_NAVEKF2_AVAILABLE=0')
+        except ValueError:
+            pass
+        env.CXXFLAGS += ['-DHAL_NAVEKF2_AVAILABLE=1']
+
         if self.with_can:
             cfg.define('HAL_NUM_CAN_IFACES', 2)
             env.DEFINES.update(CANARD_MULTI_IFACE=1,