Cleanup NRF s140 Softdevice variants (#4252)

Note: This idea is originally from @caveman99 and should be
credited as such. Submitting as a separate PR so the work in
meshtastic/firmware#4148 can be a bit cleaner and Seeed boards
can build while that work is ongoing.

The nrf52 boards that depend on the v7 softdevice all use the same
code and linker files. Rather than duplicate the code, keep it
all together with the platform.

variants/wio-tracker-wm1110/platformio.ini

@@ -1,12 +1,12 @@
-; The very slick RAK wireless RAK 4631 / 4630 board - Unified firmware for 5005/19003, with or without OLED RAK 1921
+; The red tracker Dev Board with the WM1110 module
 [env:wio-tracker-wm1110]
 extends = nrf52840_base
 board = wio-tracker-wm1110
 ; platform = https://github.com/maxgerhardt/platform-nordicnrf52#cac6fcf943a41accd2aeb4f3659ae297a73f422e
-build_flags = ${nrf52840_base.build_flags} -Ivariants/wio-tracker-wm1110 -DWIO_WM1110
+build_flags = ${nrf52840_base.build_flags} -Ivariants/wio-tracker-wm1110 -Isrc/platform/nrf52/softdevice -Isrc/platform/nrf52/softdevice/nrf52 -DWIO_WM1110
   -L "${platformio.libdeps_dir}/${this.__env__}/bsec2/src/cortex-m4/fpv4-sp-d16-hard"
   -DGPS_POWER_TOGGLE ; comment this line to disable triple press function on the user button to turn off gps entirely.
-board_build.ldscript = variants/wio-tracker-wm1110/nrf52840_s140_v7.ld
+board_build.ldscript = src/platform/nrf52/nrf52840_s140_v7.ld
 build_src_filter = ${nrf52_base.build_src_filter} +<../variants/wio-tracker-wm1110>
 lib_deps = 
   ${nrf52840_base.lib_deps}