Allow SPHAL namespace to access system in case of legacy

Allow SPHAL namespace to access system in case of legacy

In current there is limited link from sphal to platform in case of
legacy device due to absence of VNDK related library list. Anyway, SPHAL
namespace requires access to libraries under /system/lib which is
VNDK-SP in treblelized device. This change adds extra access to system
libs from SPHAL namespace in case of legacy device.

Bug: 152932503
Test: m -j passed
Change-Id: I93fc82a36cf3c2ee33c9bd1f2bb8371bb2d6d700
Merged-In: I93fc82a36cf3c2ee33c9bd1f2bb8371bb2d6d700