[pwrmgr] Fix wakeup interrupt generation
[pwrmgr] Fix wakeup interrupt generation

- fixes #9742
- qualify wakeup interrupt generation with both slow_fsm pwrup cause
  and fast fsm expectations.

- we cannot use fast fsm expectations only because it needs to know
  whether the power up event is from a reset or a wakeup.

Signed-off-by: Timothy Chen <d7b2ae30d8c0f215facd721941273067fd1d14a2@google.com>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan