watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH

watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH

The HAVE_ prefix means that the code could be enabled. Add another
variable for HAVE_HARDLOCKUP_DETECTOR_ARCH without this prefix.
It will be set when it should be built. It will make it compatible
with the other hardlockup detectors.

The change allows to clean up dependencies of PPC_WATCHDOG
and HAVE_HARDLOCKUP_DETECTOR_PERF definitions for powerpc.

As a result HAVE_HARDLOCKUP_DETECTOR_PERF has the same dependencies
on arm, x86, powerpc architectures.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>