tests: interrupt: add test cases of offloading job from isr

Add 3 test cases to test offload job from isr, include:

1. test_isr_offload_job_multiple()
Validate the offloaded work executes immediately or not depends on its
priority, and it offloads to different k_work.

2. test_isr_offload_job_identi()
Validate the offloaded work executes immediately or not depends on its
priority, and it offloads to the identical k_work.

3. test_isr_offload_job()
Use dynamic interrupt instead of irq_offload() to verify the offloaded
work.

Signed-off-by: Enjia Mai <enjiax.mai@intel.com>
3 files changed