Wrong hard-coded path to sdktool in setup_qtcreator.sh script

As mentioned in header there is a wrong hard-coded path to sdktool in setup_qtcreator.sh script of the Boot2Qt part.

So there are two solutions:

1. This line

default SDKTOOL "${DIR}/../../../../../Tools/QtCreator/bin/sdktool"

must be change to this

default SDKTOOL "${DIR}/../../../../../Tools/QtCreator/libexec/qtcreator/sdktool"

2. Return an old project structure, where sdktool was in Tools/QtCreator/bin directory