This adds the CMake equivalent to the classical -device-option key=value
configure argument:
-DQT_QMAKE_DEVICE_OPTIONS=key1=value1[;keyN=valueN]
The keys and values get dumped verbatim into qdevice.pri.
This patch also ports the machineTuple configure test. Its result is
written into qdevice.pri as value for the GCC_MACHINE_DUMP variable.
Change-Id: I29f2323fd87639fafaed99ec7446c7ee75504705
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>