build(deps): bump third_party/litex_vexriscv_smp
build(deps): bump third_party/litex_vexriscv_smp

Bumps [third_party/litex_vexriscv_smp](https://github.com/enjoy-digital/litex_vexriscv_smp) from `3cf815b` to `04680cf`.
- [Release notes](https://github.com/enjoy-digital/litex_vexriscv_smp/releases)
- [Commits](https://github.com/enjoy-digital/litex_vexriscv_smp/compare/3cf815be641309e3b1836d90fb124bc8e44b92a8...04680cf84ab9dfd6fb91195a74c583ed0710a08f)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
SymbiFlow/fpga-tool-perf,SymbiFlow/fpga-tool-perf,SymbiFlow/fpga-tool-perf,SymbiFlow/fpga-tool-perf