morello: Remove unused multichip info struct
Created by: wernerlewis
Commit ee56f02c added the Morello system module, based on the N1SDP system module. This included a declaration of the struct morello_multichip_info, which was not used. This commit removes this unused declaration.
Change-Id: I24aebb19a138137c433dcafd5dff25ae8f187b8a