doc: doxygen: show global _track_list_k_xxx variables in Doxygen

This makes for a not so pretty regex, so there might be better options,
meanwhile this ensures that what are effectively API symbols are
properly documented and visible in the API documentation.

Signed-off-by: Benjamin Cabé <[email protected]>

Author: kartben

doc/zephyr.doxyfile.in

@@ -1106,7 +1106,11 @@ EXCLUDE_PATTERNS       =
 # wildcard * is used, a substring. Examples: ANamespace, AClass,
 # ANamespace::AClass, ANamespace::*Test
 
-EXCLUDE_SYMBOLS        = _* \
+EXCLUDE_SYMBOLS        = _[^t]* \
+                         _t[^r]* \
+                         _tr[^a]* \
+                         _tra[^c]* \
+                         _trac[^k]* \
                          *.__unnamed__ \
                          z_* \
                          Z_*