* Plain RAK4631 should not compile EInk and TFT display code
* Add USE_TFTDISPLAY to variant files.
* Derp
* Undo the platformio.ini changes to heltec_v4
* Drop unneeded src_filter lines
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Co-authored-by: Jonathan Bennett <jbennett@incomsystems.biz>
Co-authored-by: Jason P <applewiz@mac.com>