build: Turn redundant path requirements error into a warning

* The change I3bf5f36125167af546dd967464a56d77f2bf3a3a added
  the vendor.lineage.power hidl interface to the exclusion list,
  however the 64 bit library is only generated by 64 bit targets.
  This would trigger the redundant requirements check for targets
  like lineage_arm or lineage_x86.

* There is really no need for this to be an error, so make it
  a warning instead.

Change-Id: I3ddf9cd6a2d8b60dc0df508c2fa14877f0f54356