cmake/zephyr: unify cmake rules for src/logging

Adding all source files in a single, giant zephyr/CMakeLists.txt is
inconvenient and does not scale.

Modify Zephyr rules to use definitions in src/logging/ instead.

Link: #8260
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

Author: kv2019i

src/logging/CMakeLists.txt

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: BSD-3-Clause
+
+add_local_sources_ifdef(CONFIG_LOG_BACKEND_SOF_PROBE sof log_backend_probe.c)

zephyr/CMakeLists.txt

@@ -210,6 +210,7 @@ add_subdirectory(../src/init/ init_unused_install/)
 add_subdirectory(../src/ipc/  ipc_unused_install/)
 add_subdirectory(../src/lib/ lib_unused_install/)
 add_subdirectory(../src/library_manager/ library_manager_unused_install/)
+add_subdirectory(../src/logging/ logging_unused_install/)
 add_subdirectory(../src/schedule/  schedule_unused_install/)
 add_subdirectory(../src/trace/ trace_unused_install/)
 add_subdirectory(test/)
@@ -476,9 +477,6 @@ zephyr_library_sources(
 # SOF module interface functions
 add_subdirectory(../src/module module_unused_install/)
 
-zephyr_library_sources_ifdef(CONFIG_LOG_BACKEND_SOF_PROBE
-      ${SOF_SRC_PATH}/logging/log_backend_probe.c)
-
 zephyr_library_sources_ifdef(CONFIG_FAST_GET lib/fast-get.c)
 
 # Optional SOF sources - depends on Kconfig - WIP