[ROCDL] Refactored MFMA ops in ODS; added constraints (#175775)
This PR improves the ROCDL MFMA intrinsics by making their operand and
result types explicit in the IR and by modeling immediate arguments
(immargs) as attributes rather than opaque operands.
This brings MFMA intrinsics in line with recent changes made to ROCDL
WMMA operations, where intrinsic signatures were clarified to avoid
treating them as an unstructured “blob of arguments”.