accelerometer: don't initialize on wake if already set up

movement.c

@@ -716,6 +716,8 @@ void app_setup(void) {
         watch_register_interrupt_callback(HAL_GPIO_BTN_ALARM_pin(), cb_alarm_btn_interrupt, INTERRUPT_TRIGGER_BOTH);
 
 #ifdef I2C_SERCOM
+        // if accelerometer was already detected and set up, no need to set it up again.
+        if (!movement_state.has_lis2dw) {
             watch_enable_i2c();
             if (lis2dw_begin()) {
                 movement_state.has_lis2dw = true;
@@ -761,6 +763,7 @@ void app_setup(void) {
             } else {
                 watch_disable_i2c();
             }
+        }
 #endif
 
         watch_enable_buzzer();