contrib: qtdeclarative: Add a dependency from qtdeclarative-tools to qtshadertools-tools

When cross building, and building the native qtdeclarative-tools (which can start before building the main qtdeclarative), these depend on tools installed by qtshadertools-tools (the native build host version of qtshadertools).

This was already a dependency for the main, cross compiled qtdeclarative target, but also is required for the qtdeclarative native tools.