instead of letting the specs validate themselves on each call, let them
only define a callback for use by the verifyspec configure test. this
is somewhat faster, and allows them to be loaded before qdevice.pri is
populated.
Change-Id: I2b60d006b33bbf42c28949f10ad429520ed32f46
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>