Rename LED_PIN to LED_POWER, move handling out of main to dedicated module (#9512)

* Rename LED_PIN to LED_POWER, move handling out of main to dedicated module

* Misc

* Remove errant endif

variants/esp32/tlora_v2_1_16/platformio.ini

@@ -22,4 +22,4 @@ build_flags =
   ${env:tlora-v2-1-1_6.build_flags}
   -DBUTTON_PIN=0
   -DPIN_BUZZER=25
-  -DLED_PIN=-1
+  -DLED_POWER=-1

variants/esp32/tlora_v2_1_16/variant.h

@@ -8,10 +8,10 @@
 #define I2C_SDA 21 // I2C pins for this board
 #define I2C_SCL 22
 
-#if defined(LED_PIN) && LED_PIN == -1
-#undef LED_PIN
+#if defined(LED_POWER) && LED_POWER == -1
+#undef LED_POWER
 #else
-#define LED_PIN 25 // If defined we will blink this LED
+#define LED_POWER 25 // If defined we will blink this LED
 #endif
 
 #define USE_RF95