linker: restore prelink support

Prelink support is required to load old vendor binary blobs
on many devices properly

This commit partially reverts 4688279db5dcc4004941e7f133c4a1c3617d842c

Change-Id: Iee5325e048daee78e8dcaa47c87454b908c89b4e

Conflicts:

	linker/linker_phdr.cpp