tp: Parsing device_pm_callback_[start|end] ftrace events

This patch does the following:
- Parses `device_pm_callback_[start|end]` ftrace events to capture
  information about the device, associated driver, type of callback etc.
- Creates perfetto slices to visualize device PM callbacks executed
  during a suspend / resume cycle and adds them to the "Suspend / Resume
  Latency" UI track.
- The display name format for the slices is:
  "<driver name> <device name> <event type>[:<callback phase>]"

A 60s trace with ~9 suspend/resume cycles was used to measure the load
times on the UI (via the `perfetto.AsyncSlices` plugin). The size of the
trace was 41MB.

Load times (averaged across 3 runs)
With this change: 51 ms
Without this change: 28 ms

The increase in ftrace_event table entries processed for the "Suspend /
Resume Latency" track correspond to `device_pm_callback_[start|end]`
events.

```
$ select COUNT(*) from ftrace_event where name like "device_pm_callback%";
91622

$ select COUNT(*) from ftrace_event where name like "suspend_resume%";
502
```

Bug: 330333710
Change-Id: I873efd72a3db271075d5507e03b8b298422348a3