lima: expose fragment shader derivatives capability

lima: expose fragment shader derivatives capability

Support for fragment shader derivatives has landed in the Lima PP
compiler for a long time, but its capability is not exposed yet.

Expose the support now.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3944>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3944>