watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY

The dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY was more complicated
than it needed to be.  If the "perf" detector is available and we have SMP
then we have a choice, so enable the config based on just those two config
items.

Link: https://lkml.kernel.org/r/20230526184139.8.I49d5b483336b65b8acb1e5066548a05260caf809@changeid


Signed-off-by: Douglas Anderson <dianders@chromium.org>
Suggested-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>