sim: add noreturn markings to more hw abort/halt funcs

sim: add noreturn markings to more hw abort/halt funcs

These functions either call abort() themselves, or call functions which
are already marked noreturn.  Either way, they don't return, so mark them
as such so calling code can assume this.  This fixes some uninitialized
warnings due to code paths that end in an abort function.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>