locking/lockdep: Enforce PROVE_RAW_LOCK_NESTING only if ARCH_SUPPORTS_RT

Relax the rule to set PROVE_RAW_LOCK_NESTING by default only for arches
that supports PREEMPT_RT.  For arches that do not support PREEMPT_RT,
they will not be forced to address unimportant raw lock nesting issues
when they want to enable PROVE_LOCKING.  They do have the option
to enable it to look for these raw locking nesting problems if they
choose to.

Suggested-by: Guenter Roeck <[email protected]>
Signed-off-by: Waiman Long <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Guenter Roeck <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Waiman-Long

lib/Kconfig.debug

@@ -1397,9 +1397,9 @@ config PROVE_LOCKING
 	 For more details, see Documentation/locking/lockdep-design.rst.
 
 config PROVE_RAW_LOCK_NESTING
-	bool
+	bool "Enable raw_spinlock - spinlock nesting checks" if !ARCH_SUPPORTS_RT
 	depends on PROVE_LOCKING
-	default y
+	default y if ARCH_SUPPORTS_RT
 	help
 	 Enable the raw_spinlock vs. spinlock nesting checks which ensure
 	 that the lock nesting rules for PREEMPT_RT enabled kernels are