Add support for Xpulp related extensions

Placeholder github Source User
2026-03-29T09:12:33Z

Based on [instruction_set_extensions spec in cv32e40p](https://github.com/openhwgroup/cv32e40p/blob/b02bc43d8f23dd75adadcfb355fa841447e19b9c/docs/source/instruction_set_extensions.rst)

Xpulp extensions can be enabled by adding parameter "-cpu rv32,xcvalu=true,xcvbi=true,xcvbitmanip=true,xcvhwlp=true,xcvmac=true,xcvmem=true,xcvsimd=true" to qemu-riscv32 or qemu-system-riscv32, such as we can run riscv32 application by
```
qemu-riscv32 -cpu rv32,xcvalu=true,xcvbi=true,xcvbitmanip=true,xcvhwlp=true,xcvmac=true,xcvmem=true,xcvsimd=true
<path-to-app>
```