Update RVFI to correctly handle "in_trap" for vectored CLIC interrupts

Created by: silabs-oysteink

For vectored CLIC interrupts, the following events happen:

1. IRQ becomes pending
2. IRQ is taken, irq_ack=1
3. Pointer is fetched
4. A jump is performed to the loaded pointer
5. First instruction of handler arrives in IF

It is easy to adapt the RVFI in_trap logic to detect the first instruction of the handler, but the assertion "a_irq_ack_rvfi_capture" needs a bit more work to handle the larger delay between irq_ack and the first handler instruction.