Tracing hooks problem on POSIX

[MarekPieta]

Describe the bug
Tracing hook do not work properly on POSIX (native) architecture.

To Reproduce
Steps to reproduce (using philosophers example):

1. mkdir build; cd build
2. cmake .. -DBOARD=native_posix
3. In menuconfig add "Tracing via Common Trace Format Support"
4. make run
5. See the log (for example with babeltrace)

Expected behavior
Thread swtiching in and out should match (we shouldn't have multiple logs from thread switching in in a row without thread switching out). Similar problem occurs for isr_enter (there is no matching isr_exit).

Impact
Current tracing hooks are not going to work properly for debug purposes on POSIX architecture.

Screenshots or console output

[01:00:00.018720000] (+0.000000000) 0 thread_pending: { thread_id = 134560504 }
[01:00:00.018720000] (+0.000000000) 0 thread_switched_out: { thread_id = 134560504 }
[01:00:00.018720000] (+0.000000000) 0 thread_switched_in: { thread_id = 134560504 }
[01:00:00.018720000] (+0.000000000) 0 thread_switched_in: { thread_id = 134560416 }
[01:00:00.018720000] (+0.000000000) 0 thread_switched_out: { thread_id = 134560416 }
[01:00:00.018720000] (+0.000000000) 0 thread_switched_in: { thread_id = 134560416 }
[01:00:00.018720000] (+0.000000000) 0 thread_switched_in: { thread_id = 134562080 }
[01:00:00.018720000] (+0.000000000) 0 idle:
[01:00:00.018730000] (+0.000010000) 0 isr_enter:
[01:00:00.018730000] (+0.000000000) 0 idle:
[01:00:00.018740000] (+0.000010000) 0 isr_enter:
[01:00:00.018740000] (+0.000000000) 0 idle:
[01:00:00.018750000] (+0.000010000) 0 isr_enter:
[01:00:00.018750000] (+0.000000000) 0 idle:
[01:00:00.018760000] (+0.000010000) 0 isr_enter:
[01:00:00.018760000] (+0.000000000) 0 idle:

Environment:

• OS: Ubuntu 16.04 LTS
• Toolchain: Zephyr SDK 0.9.5

[aescolar]

Will try to send a patch today (it is quite obvious)
(It is very nice that you already raise issues, so we fix them. Though note that that 1st PR just added the start of the CTF support and a few more should be coming)