openssl: rewrite ptest installation

openssl: rewrite ptest installation

Rewrite (again) the openssl test suite installation.

Depend on and reuse already installed libraries and modules instead of
installing them twice.

Be more selective when installing from the build tree so we don't install
intermediate .c .d .o files.

This further reduces the size of openssl-dbg from ~120MB to ~18MB.

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