glsl: remove Lower{TCS,TES}PatchVerticesIn

glsl: remove Lower{TCS,TES}PatchVerticesIn

Intel was the only user and now NIR can do the lowering.

v2: do not try to handle it as a system value directly for the SPIR-V
    path. In GL we rather handle it as a uniform like we do for the
    GLSL path (Jason).

v3: drop LowerTESPatchVerticesIn as well (Jason)

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>