Preliminary Thinknode M4 Support (#8754)

* Preliminary Thinknode M4 Support

* oops

* Fix RF switch TX configuration

* trunk'd

* GPS fix for M4

* Battery handling and LED for M4

* Trunk

* Drop debug warnings

* Make Red LED notification

* Merge cleanup

* Make white LEDs flash during charge

---------

Co-authored-by: Jonathan Bennett <jbennett@incomsystems.biz>

variants/nrf52840/ELECROW-ThinkNode-M4/platformio.ini

@@ -0,0 +1,15 @@
+; ThinkNode M4 - Powerbank nrf52840/LR1110 by Elecrow
+[env:thinknode_m4]
+extends = nrf52840_base
+board = ThinkNode-M4
+board_check = true
+debug_tool = jlink
+
+build_flags = ${nrf52840_base.build_flags}
+  -Ivariants/nrf52840/ELECROW-ThinkNode-M4
+  -DELECROW_ThinkNode_M4
+
+build_src_filter = ${nrf52_base.build_src_filter} +<../variants/nrf52840/ELECROW-ThinkNode-M4>
+lib_deps =
+  ${nrf52840_base.lib_deps}
+  lewisxhe/PCF8563_Library@^1.0.1