vndk-def: Exclude vndk-sp from vndk

This commit excludes vndk-sp libraries from vndk result sets.  This CL
eliminates several false warnings on vendor usages on libhwbinder.so

Bug: 37867089
Test: Warnings on libhwbinder.so usages disappeared given sailfish
images.

Change-Id: Icc3b07bc6a57e41a3fcbaf116c1316f77e7a439d