Appropriately filter data based on -D and -H options (#163)

- Addresses concern that device metric tracks are still shown in Perfetto trace file even when only -H is specified to rocprof-sys-sample (and vice versa).
- Update sampling call-stack docs.

[ROCm/rocprofiler-systems commit: 8ae6651357]

projects/rocprofiler-systems/source/lib/core/config.hpp

@@ -216,6 +216,9 @@ get_use_sampling() ROCPROFSYS_HOT;
 bool&
 get_use_process_sampling() ROCPROFSYS_HOT;
 
+bool&
+get_cpu_freq_enabled();
+
 bool&
 get_use_pid();