ktest: Use Kconfig dependencies to shorten time to make min_config

To save time, the test does not just grab any option and test
it. The Kconfig files are examined to determine the dependencies
of the configs. If a config is chosen that depends on another
config, that config will be checked first. By checking the
parents first, we can eliminate whole groups of configs that
may have been enabled.

For example, if a USB device config is chosen and depends on
CONFIG_USB, the CONFIG_USB will be tested before the device.
If CONFIG_USB is found not to be needed, it, as well as all
configs that depend on it, will be disabled and removed from
the current min_config.

Note, the code from streamline_config (make localmodconfig)
was copied and used to find the dependencies in the Kconfig file.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>