zink: enable cull-distance if supported

This is already implemented, and we just need to flip the switch to turn
it on.

Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5479>

src/gallium/drivers/zink/zink_screen.c

@@ -270,10 +270,8 @@ zink_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_PCI_FUNCTION:
       return 0; /* TODO: figure these out */
 
-#if 0 /* TODO: Enable me */
    case PIPE_CAP_CULL_DISTANCE:
       return screen->feats.shaderCullDistance;
-#endif
 
    case PIPE_CAP_VIEWPORT_SUBPIXEL_BITS:
       return screen->props.limits.viewportSubPixelBits;