i915g: Force 1D textures to use wrap mode for the Y coordinate.

There are no 1D textures in HW, so we use 2D, but at the shader level
there no Y coordinate to 1D sampling, so we need that value to be ignored.
WRAP mode can get us that.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11457>