tu: Fix setting RB_DEPTH_CNTL::Z_CLAMP_ENABLE

tu: Fix setting RB_DEPTH_CNTL::Z_CLAMP_ENABLE

I missed this when enabling pipeline libraries, and we were also setting
this to the wrong thing. Previously we were using rasterization state
when parsing depth/stencil indirectly via builder->depth_clip_disable,
which is not allowed with pipeline libraries. Fixing this is a bit
painful because now RB_DEPTH_CNTL can depend on state from both the
fragment shader library and the pre-rasterization library, in addition
to being disabled via output interface state.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18861>