cmake: options: set default install bin/lib dir
cmake: options: set default install bin/lib dir

In case CMAKE_INSTALL_BINDIR/LIBDIR not set, set with default
value

Signed-off-by: Wendy Liang <cac46fad14f88489ab4dbc3c1082c7dafae20187@xilinx.com>

forg0ne/libmetal,forg0ne/libmetal