[mlir][rocdl] Add xdlops intrinsics to rocdl dialect

Summary: This adds xdlops (mfma) to the rocdl dialect and also tests the translation to llvm ir.

Reviewers: ftynse

Subscribers: mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, stephenneuendorffer, Joonsoo, grosul1, frgossen, Kayjukh, llvm-commits

Tags: #llvm #mlir

Differential Revision: https://reviews.llvm.org/D79642