Add config flags to variants

variants/waveshare_rp2040_lora/platformio.ini

@@ -35,6 +35,9 @@ build_flags = ${waveshare_rp2040_lora.build_flags}
   -D ADVERT_LON=0.0
   -D ADMIN_PASSWORD='"password"'
   -D MAX_NEIGHBOURS=8
+;  -D BRIDGE_OVER_SERIAL=Serial2
+;  -D BRIDGE_OVER_SERIAL_RX=9
+;  -D BRIDGE_OVER_SERIAL_TX=8
 ;  -D MESH_PACKET_LOGGING=1
 ;  -D MESH_DEBUG=1
 build_src_filter = ${waveshare_rp2040_lora.build_src_filter}