cmake: improve Vulkan cooperative matrix support checks#2966

ggerganov merged 1 commit intoggml-org:masterggml-org/whisper.cpp:masterfrom

sandrohanea:sandro/fix-outsidedef-for-vulkan-coopmatsandrohanea/whisper.cpp:sandro/fix-outsidedef-for-vulkan-coopmatCopy head branch name to clipboard