[mlir] Apply ClangTidy findings

Remove unused using declarations

Author: akuegel

mlir/tools/mlir-linalg-ods-gen/mlir-linalg-ods-yaml-gen.cpp

@@ -31,9 +31,6 @@
 using namespace mlir;
 
 using llvm::yaml::Input;
-using llvm::yaml::MappingTraits;
-using llvm::yaml::ScalarEnumerationTraits;
-using llvm::yaml::ScalarTraits;
 
 #define DEBUG_TYPE "linalg-ods-gen"