UPSTREAM: console: Expand dummy functions for CFI

This expands the no-op dummy functions into full prototypes to avoid
indirect call mismatches when running under Control Flow Integrity
checking, like with Clang's -fsanitize=cfi.

Co-Developed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Change-Id: If63cf04ad86b55afb1442ef4037b5f575457ea06
(cherry picked from commit c396a5bf457fb60159dcedbd4f48d53a62be030a)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>