freedreno/ir3: Replace our custom vec4 UBO intrinsic with the shared lowering.

freedreno/ir3: Replace our custom vec4 UBO intrinsic with the shared lowering.

This gets us fewer comparisons in the shaders that we need to optimize
back out, and reduces backend code.

total instructions in shared programs: 11547270 -> 7219930 (-37.48%)
total full in shared programs: 334268 -> 319602 (-4.39%)

Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6378>