[llvm-readobj] - Teach readobj to print DT_FILTER dynamic tag in human readable form.

[llvm-readobj] - Teach readobj to print DT_FILTER dynamic tag in human readable form.

Nothing special here, output format is similar to the format
used by binutils readelf and ELF Tool Chain readelf.

Differential revision: https://reviews.llvm.org/D35351

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308033 91177308-0d34-0410-b5e6-96231b3b80d8