python3-libarchive-c: Avoid using find_library python API

python3-libarchive-c: Avoid using find_library python API

find_library API depends on platform to provide ldconfig, ld, gcc, objdump
etc, so either we add these dependencies or avoid them by computing the
libarchive library name during build, which we can be done.

This ensures that ffi module works with musl as well as glibc equally
as musl does not provide ldconfig like glibc does

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Cc: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>