intel: ASTC support was removed on Gfx12.5

On Gfx12.5+, they've removed the ASTC hardware. On ANV, this means we need to disable support for all the ASTC formats as well as disable the textureCompressionASTC_LDR feature bit. In iris, it means that ASTC textures will get automatically decompressed behind the scenes. If they transcode_astc driconf option is set, they will get transcoded to DXT5 at slightly reduced quality for better perf and memory usage.