[NEW] graphics/stable-diffusion.cpp

Here's a port for graphics/stable-diffusion.cpp

Description

Diffusion model inference in pure C/C++

WWW: https://github.com/leejet/stable-diffusion.cpp

Maintainer

The OpenBSD ports mailing-list

While it *is* based on libggml, the sd-cpp ggml is built with
GGML_MAX_NAME=128, so we can't use devel/libggml from ports.

Likewise, we can't dynamically select the backend as in llama.cpp,
hence the -vulkan FLAVOR.

Works fine on amd64 - it's a bit more pointless without a discrete
graphics card and substantial amounts of VRAM, however.

ok?