ktest: Sort make_min_config configs by dependecies

The make_min_config test will turn off one config at a time and check
if the config boots or not, and if it does, it will remove that config
plus any config that depended on that config.

ktest already looks if a config has a dependency and will try the
dependency config first. But by sorting the configs and trying the
config with the most configs dependent on it, we can shrink the
minconfig faster.

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