Added CV32E40P example constraints

Created by: Silabs-ArjanB

Hi @davideschiavone Can you please review these example constraints?

Could you also close/reject the following as I think we should not be adding tool/technology specific flows in this repos (that could be done in core-v-mcu if we have the need for it)

• https://github.com/openhwgroup/cv32e40p/pull/305
• https://github.com/openhwgroup/cv32e40p/pull/273

Signed-off-by: Arjan Bink Arjan.Bink@silabs.com