virgl: extend resource_info with planes and modifiers

It's becoming commonplace that DRM drivers make use of 'modifiers' that alter the in-memory representation of a texture, which means that when importing a texture the same exact 'modifiers' must be specified along with the other usual parameters.

Rename vrend_winsys_get_fourcc_for_texture() to vrend_winsys_get_attrs_for_texture() and extend it to receive 'planes' and 'modifiers'.

Do the same thing for virgl_egl_get_fourcc_for_texture(), renaming it to virgl_egl_get_attrs_for_texture().

Then, extend struct virgl_renderer_resource_info with fields to hold 'planes' and 'modifiers'.

Signed-off-by: Sergio Lopez slp@redhat.com