mesa/texstore: Use Driver.CompressedTexSubImage in the default CompressedTexImage
mesa/texstore: Use Driver.CompressedTexSubImage in the default CompressedTexImage

Enable drivers to use their own implementation of this method instead of
the mesa default. Since the drivers that currently overwrite
dd_function_table::CompressedTexSubImage also overwrite
::CompressedTexImage, there should be no behavioral change.

Signed-off-by: Nanley Chery <d78cd5d33e98a5581566f188959f731bd0b1c0fd@intel.com>
Reviewed-by: Nicolai Hähnle <0d0be6cf5ad662651be2dc5dfd44aa2b09d4c1cc@amd.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler