[Backport] Refactor and fix creation of ElementWise Region for Gemm+Gemm like ops#1965

umangyadav merged 2 commits intorelease/rocm-rel-7.0ROCm/rocMLIR:release/rocm-rel-7.0from

cpfixGemmBlockArgsROCm/rocMLIR:cpfixGemmBlockArgsCopy head branch name to clipboard