accel/amdxdna: Refactor hardware context destroy routine

It is required by firmware to wait up to 2 seconds for pending commands
before sending the destroy hardware context command. After 2 seconds
wait, if there are still pending commands, driver needs to cancel them.

So the context destroy steps need to be:
  1. Stop drm scheduler. (drm_sched_entity_destroy)
  2. Wait up to 2 seconds for pending commands.
  3. Destroy hardware context and cancel the rest pending requests.
  4. Wait all jobs associated with the hwctx are freed.
  5. Free job resources.

Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250124173536.148676-1-lizhi.hou@amd.com