[ibex] Upstream prim changes and remove patches

[andreaskurth]

PRs #25654 and #25736 modify the I/Os of prims instantiated in Ibex. To break a dependency cycle (Ibex vendors those prims from OT, and OT vendors Ibex), that PR patches Ibex in OT to be compatible with the changed prims.

Those changes to Ibex and the prims need to be upstreamed to https://github.com/lowRISC/ibex, and then Ibex needs to be re-vendored into OT without patches.