qitoolchain: overwrite toolchain.cmake only when it change
qitoolchain: overwrite toolchain.cmake only when it change

aldebaran/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,dmerejkowsky/qibuild,dmerejkowsky/qibuild