qcom: Include vendor/qcom/opensource/display namespace only for <5.10 platforms

hardware/qcom-caf/sm8450/display contains its own copies of
* libgralloc.qti
* libqdMetaData
* libdisplayconfig.qti

Including this namespace too, results in a module already defined error

Change-Id: I7d5c861307f4d517d5b53c6444897a4b90f0095e