zink: make all xfb caps depend on extension

Without this, we'll expose GL_ARB_transform_feedback2 and
GL_ARB_transform_feedback3 even without VK_EXT_transform_feedback,
because these caps are directly wired up without checking the pervious
extensions.

Fixes: e8ad52f7b0c ("zink: enable xfb extension in screen creation")
Reviewed-by: Hoe Hao Cheng <haochengho12907@gmail.com>
Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8640>
(cherry picked from commit 855370bb620663b5e451e08046e4ddb4b6429c0b)
2 files changed