GL_ARB_texture_compression_bptc marked as unsupported on Panfrost

[kusma]

The text in features.txt for GL_ARB_texture_compression_bptc, is DONE (all drivers that supports EXT_texture_sRGB and OES_texture_half_float). Panfrost supports both of these extensions, as well as GL_ARB_texture_compression_bptc itself.

Something is incorrectly marking some driver as exposing it, while some other drivers as not exposing it, and I don't think that's correct.