tracing: move tracing under subsys/

Tracing subsystem is growing and although related to debugging, it does
deserve to belong into its own subsystem.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

subsys/tracing/CMakeLists.txt

@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: Apache-2.0
+
+if(CONFIG_SEGGER_SYSTEMVIEW OR CONFIG_TRACING_CPU_STATS)
+
+  zephyr_sources_ifdef(
+    CONFIG_SEGGER_SYSTEMVIEW
+    sysview_config.c
+    sysview.c
+    )
+
+  zephyr_sources_ifdef(
+    CONFIG_TRACING_CPU_STATS
+    cpu_stats.c
+    )
+endif()
+
+zephyr_sources_ifdef(
+  CONFIG_TRACING
+  tracing_buffer.c
+  tracing_core.c
+  tracing_format_common.c
+  )
+
+zephyr_sources_ifdef(
+  CONFIG_TRACING_SYNC
+  tracing_format_sync.c
+  )
+
+zephyr_sources_ifdef(
+  CONFIG_TRACING_ASYNC
+  tracing_format_async.c
+  )
+
+zephyr_sources_ifdef(
+  CONFIG_TRACING_BACKEND_USB
+  tracing_backend_usb.c
+  )
+
+zephyr_sources_ifdef(
+  CONFIG_TRACING_BACKEND_UART
+  tracing_backend_uart.c
+  )
+
+zephyr_sources_ifdef(
+  CONFIG_TRACING_BACKEND_POSIX
+  tracing_backend_posix.c
+  )
+
+zephyr_include_directories_ifdef(
+  CONFIG_TRACING
+  ${ZEPHYR_BASE}/kernel/include
+  ${ZEPHYR_BASE}/arch/${ARCH}/include
+)
+
+zephyr_include_directories_ifdef(CONFIG_TRACING include)
+
+add_subdirectory_ifdef(CONFIG_TRACING_CTF ctf)