selftests/amd-pstate: Fix broken paths to run workloads in amd-pstate-ut

In selftests/amd-pstate, tbench and gitsource microbenchmarks are
used to compare the performance with different governors. In current
implementation the relative path to run `amd_pstate_tracer.py` is broken.
Fix this by using absolute paths.

Signed-off-by: Swapnil Sapkal <swapnil.sapkal@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

PM: tools: use canonical ftrace path

The canonical location for the tracefs filesystem is at /sys/kernel/tracing.

But, from Documentation/trace/ftrace.rst:

Before 4.1, all ftrace tracing control files were within the debugfs
file system, which is typically located at /sys/kernel/debug/tracing.
For backward compatibility, when mounting the debugfs file system,
the tracefs file system will be automatically mounted at:

/sys/kernel/debug/tracing

A few scripts in tools/power still refer to this older debugfs path, so
let's update them to avoid confusion.

Signed-off-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

tools/power/x86/amd_pstate_tracer: Add tracer tool for AMD P-state

Intel P-state tracer is a useful tool to tune and debug Intel P-state
driver. AMD P-state tracer import intel pstate tracer. This tool can
be used to analyze the performance of AMD P-state tracer.

Now CPU frequency, load and desired perf can be traced.

Signed-off-by: Jinzhou Su <Jinzhou.Su@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>