Remove *.dep files for ld.config.txt, [llndk|vndksp].libraries.txt

The dep files are not required because change in the command line
triggers the rule.

Test: m -j ld.config.txt llndk.libraries.txt vndksp.libraries.txt
Re-run the build after adding or removing libs to/from the vndk set.
The txt files are updated accordingly.

Change-Id: I9c9e22088cc2afeb66e8b159f611b25d698cf800