[XPU] [Feature] [2/3] add fp8 scaled_mm_v2 implementation for XPU (pytorch#167518)

This PR implements `scaled_mm_v2` for XPU follows the work in pytorch#164141 .
## PR stack:

- pytorch#165978 : implementation of XPU scaled_mm and oneDNN kernel
- -> pytorch#167518 : implementation of XPU scaled_mm_v2
- pytorch#166056 : Op registration

Pull Request resolved: pytorch#167518
Approved by: https://github.com/EikanWang, https://github.com/liangan1

Author: Stonepia