ktest: Do not ask for some options if the only test is build

When creating a ktest config or if te config only has build only
tests, some of the manditory config options are not needed.

Do not ask for them if all tests in the config file are just build
tests.

Suggested-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>