[pt2e][xnnpack_quantizer] quantize "mul" (#110428)
Adding "mul" to list of partitions that are supported by the quantizer. This shows up in EDSR, where we still want to quantize the mul op
Differential Revision: [D49850151](https://our.internmc.facebook.com/intern/diff/D49850151/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110428
Approved by: https://github.com/jerryzh168
ghstack dependencies: #110427
