arch/Kconfig: update HAVE_RELIABLE_STACKTRACE description

save_stack_trace_tsk_reliable() is not the only function providing the
reliable stack traces anymore.  Architecture might define ARCH_STACKWALK
which provides a newer stack walking interface and has
arch_stack_walk_reliable() function.  Update the description accordingly.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: http://lkml.kernel.org/r/20200120154042.9934-1-mbenes@suse.czSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/Kconfig

@@ -738,8 +738,9 @@ config HAVE_STACK_VALIDATION
 config HAVE_RELIABLE_STACKTRACE
 	bool
 	help
-	  Architecture has a save_stack_trace_tsk_reliable() function which
-	  only returns a stack trace if it can guarantee the trace is reliable.
+	  Architecture has either save_stack_trace_tsk_reliable() or
+	  arch_stack_walk_reliable() function which only returns a stack trace
+	  if it can guarantee the trace is reliable.
 
 config HAVE_ARCH_HASH
 	bool