qcom: Add dataservices to project pathmap

* Set vendor/qcom/opensource/dataservices as the default dataservices
  provider.
* Devices can override this choice by setting
  USE_DEVICE_SPECIFIC_DATASERVICES and providing dataservices in the
  $(TARGET_DEVICE_DIR)/dataservices directory.
* Set $(TARGET_DEVICE_DIR)/dataservices as the default dataservices
  provider for non-QC hardware (Nexus devices).

Change-Id: Ie003110d7b745367947b4b728bc83800c0351068