Update ld.config.txt for adbd apex

ld.config.txt for ADBD APEX works properly, but it can be reduced into
simpler way. This change updates ADBD APEX linker configuration which
reduces complexity and limit library usage from system partition.

Test: m -j && confirmed adbd works from cuttlefish
Change-Id: Ifcf1323082148aec4b6417c0ba7df0d9fe8ffeb0