gcc: depend on zstd

gcc: depend on zstd

Add zstd LTO support for target and nativesdk compiler.

This also brings gcc into sync with gcc-cross.

% x86_64-oe-linux-gcc -v
[...]
Supported LTO compression algorithms: zlib zstd
gcc version 12.2.0 (GCC)
% x86_64-oesdk-linux-gcc -v
[...]
Supported LTO compression algorithms: zlib
gcc version 12.2.0 (GCC)

Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>