stress-ng: upgrade 0.19.02 -> 0.19.03

stress-ng: upgrade 0.19.02 -> 0.19.03

Improvements
    More progress feedback when sending ^C (SIGINT)
    Clean up manual
    Improved portability

Changelog:
   https://github.com/ColinIanKing/stress-ng/releases/tag/V0.19.03

Re-enable DEBUG_BUILDs since the upstream defect:
   https://github.com/ColinIanKing/stress-ng/issues/315
is resolved by:
   6e62dc1fb   2023-08-31   Makefile: force vnni to be built with at least -O2

Signed-off-by: Randy MacLeod <Randy.MacLeod@windriver.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>