AP_BoardConfig: split setup of safety switch init init_safety()

this allows it to be called late, so that servo outputs are fully
setup before the safety is disabled when BRD_SAFETYENABLE=0

libraries/AP_BoardConfig/AP_BoardConfig.cpp

@@ -213,3 +213,10 @@ void AP_BoardConfig::set_default_safety_ignore_mask(uint16_t mask)
     px4_setup_safety_mask();
 #endif
 }
+
+void AP_BoardConfig::init_safety()
+{
+#if CONFIG_HAL_BOARD == HAL_BOARD_PX4 || CONFIG_HAL_BOARD == HAL_BOARD_VRBRAIN
+    px4_init_safety();
+#endif
+}

libraries/AP_BoardConfig/AP_BoardConfig.h

@@ -16,6 +16,7 @@ public:
     };
 
     void init(void);
+    void init_safety(void);
 
     static const struct AP_Param::GroupInfo var_info[];
 
@@ -128,7 +129,7 @@ private:
     void px4_drivers_start(void);
     void px4_setup(void);
     void px4_setup_pwm(void);
-    void px4_setup_safety(void);
+    void px4_init_safety(void);
     void px4_setup_safety_mask(void);
     void px4_setup_uart(void);
     void px4_setup_sbus(void);

libraries/AP_BoardConfig/px4_drivers.cpp

@@ -145,12 +145,10 @@ void AP_BoardConfig::px4_setup_safety_mask()
 }
 
 /*
-  setup safety switch
+  init safety state
  */
-void AP_BoardConfig::px4_setup_safety()
+void AP_BoardConfig::px4_init_safety()
 {
-    px4_setup_safety_mask();
-
     if (px4.safety_enable.get() == 0) {
         hal.rcout->force_safety_off();
         hal.rcout->force_safety_no_wait();
@@ -533,7 +531,7 @@ void AP_BoardConfig::px4_setup()
 {
     px4_setup_peripherals();
     px4_setup_pwm();
-    px4_setup_safety();
+    px4_setup_safety_mask();
     px4_setup_uart();
     px4_setup_sbus();
     px4_setup_drivers();