Towards adding CONFIG_UTRACE support for non-mmu m68k add
arch_has_single_step, and its support functions user_enable_single_step()
and user_disable_single_step().
[Geert] m68k conflict resolution from linux-next
Signed-off-by: NGreg Ungerer <gerg@uclinux.org>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>