ktest: Add CONFIG_BISECT_GOOD option

Currently the config_bisect compares the min config with the
CONFIG_BISECT config. There may be another config that we know
is good that we want to ignore configs on. By passing in this
config it will ignore the options that are set in the good config.

Note: This only ignores the config, it does not (yet) handle
options that are different between the two configs. If the good
config has "SLAB" set and the bad config has "SLUB" it will not
find the bug if the bug had to do with changing these two options.

This is something that I intend to implement in the future.

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