Make lldb-gdbserver configure/(g)make build parity with cmake.

This now builds lldb-gdbserver on all Linux and FreeBSD architectures
rather than being locked to x86_64 architectures only.

Please note lldb-gdbserver is not yet functional, this just enables
the non-x86_64 Linux/FreeBSD build using the configure/make build
system.

 --This line, and
those below, will be ignored--

M    tools/Makefile

llvm-svn: 207556