power_mgr and power_states: need build option to keep the app exiting in "active" state

[zephyrbot]

Reported by Sharron LIU:

"zephyr/tests/power/power_states" and "zephyr/samples/power/power_mgr" toggling power states in indefinite loops... This introduces issue, when we try to add such app into the automatic nightly execution.
The test case following this app's execution, will start with an uncertain SOC state. If it happened that this app toggling to "Deep sleep" state, the "make flash" of its successive test case will be failed.

So, I would suggest to provide a build option for the app to exit in active state after one loop. Please evaluate this. Thanks.

(Imported from Jira ZEP-2163)

[nashif]

@ramakrishnapallala any update on this? Was this already fixed?

[ramakrishnapallala]

@nashif I will submit the changes to the run the loop only for a certain number of times.