n1sdp: remove unused multichip info structure
Created by: wernerlewis
Commit 39808081 added support for N1SDP multichip configurations, using the struct n1sdp_multichip_info. Commit d2efba33 merged multichip information into a new structure, but did not remove the declaration of n1sdp_multichip_info. This commit removes the declaration.
Change-Id: I3b14f568c7884ea3cb140fb7f2052c4e4dfe0673