Merge pull request #4002 from jflyper/bfdev-remove-reference-to-TIMER_OUTPUT_ENABLED

Fix serial_escserial.c to use TIM_USE_MOTOR instead of TIMER_OUTPUT_ENABLED

src/main/drivers/serial_escserial.c

@@ -944,7 +944,7 @@ void escEnablePassthrough(serialPort_t *escPassthroughPort, uint16_t output, uin
     else {
         uint8_t first_output = 0;
         for (int i = 0; i < USABLE_TIMER_CHANNEL_COUNT; i++) {
-            if (timerHardware[i].output & TIMER_OUTPUT_ENABLED) {
+            if (timerHardware[i].usageFlags & TIM_USE_MOTOR) {
                 first_output = i;
                 break;
             }