lib/Kconfig.debug: enable RUNTIME_TESTING_MENU

lib/Kconfig.debug: enable RUNTIME_TESTING_MENU

Commit d3deafaa8b5c ("lib/: make RUNTIME_TESTS a menuconfig to ease
disabling it all") causes a regression when using runtime tests due to
it defaults RUNTIME_TESTING_MENU to not set.

Link: http://lkml.kernel.org/r/[email protected]
Fixes: d3deafaa8b5c ("lib/: make RUNTIME_TESTS a menuconfig to easedisabling it all")
Signed-off-by: Anders Roxell <[email protected]>
Cc: Vincent Legoll <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Byungchul Park <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>