Allow sphal to load some LLNDK for legacy devices.

For devices disabling treble, some VNDK-SP libraries needs to be loaded
as LLNDK. The CL modifies ld.config.txt to allow to load them from sphal.

Bug: 140781725
Test: Boot and check logcat. No native crash from mediaswcodec
Change-Id: Iec24405ec78359d78f4e7f43d9d046f3c70ff129