Ignore this - it's Dependency Walker ignoring how Windows looks for DLLs. Windows x64 will skip over any "wrong architecture" DLLs as it searches PATH. It mystifies me why Dependency Walker has kept this confusing misbehavior for so long.
Note that you don't "link with DLLs". You link to an export library that gives a DLL name. When you run the EXE, Windows will search in various places for a DLL with that name. (This changes a bit if the DLL was in a shared assembly, but the basic situation is the same.)
Bottom line - ignore Dependency Walker complaining about a wrong-architecture DLL unless your program doesn't run.