habanalabs: move event handling to common firmware file

Instead of writing similar event handling code for each ASIC, move the code
to the common firmware file. This code will be used for GAUDI and all
future ASICs.

In addition, add two new fields to the auto-generated events file: valid
and description. This will save the need to manually write the events
description in the source code and simplify the code.

Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>