[mlir][spirv] Use ODS generated attribute names for op definitions (#81552)

Since ODS generates getters functions for SPIRV operations' attribute
names, we replace instances of these hardcoded strings in the SPIR-V
dialect's op parser/printer with function calls for consistency.

Fixes https://github.com/llvm/llvm-project/issues/77627



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Co-authored-by: Lei Zhang <antiagainst@gmail.com>