ztest was not working with unified kernel and v1 APIs and not many tests are
using ztest right now, so instead of making it work with old APIs, convert it
to unified kernel completely so that new tests written using ztest would be
unified kenrel based.
Change-Id: Ibfcc7783dcb266abbd388662ba61c4b55d32b10c
Signed-off-by: Anas Nashif <anas.nashif@intel.com>