led output level config

[mmadela]

T Beam has a LED (a red one in fact) on pin 4, but in opposite to other boards (like TTGO Lora 2.1) it has the cathode connected to the GPIO, not the anode as others, so an inverse logic is required to signal LoRa message reception

please add corresponding setting to set active level

[mmadela]

0001-config-for-led-output-active-level.patch.txt this works for me, maybe some defaults are still necessary for some hardware