powerpc: Activate HAVE_RELIABLE_STACKTRACE for all

CONFIG_HAVE_RELIABLE_STACKTRACE is applicable to all, no
reason to limit it to book3s/64le
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/955248c6423cb068c5965923121ba31d4dd2fdde.1615881400.git.christophe.leroy@csgroup.eu

arch/powerpc/Kconfig

@@ -235,7 +235,7 @@ config PPC
 	select MMU_GATHER_RCU_TABLE_FREE
 	select MMU_GATHER_PAGE_SIZE
 	select HAVE_REGS_AND_STACK_ACCESS_API
-	select HAVE_RELIABLE_STACKTRACE		if PPC_BOOK3S_64 && CPU_LITTLE_ENDIAN
+	select HAVE_RELIABLE_STACKTRACE
 	select HAVE_SOFTIRQ_ON_OWN_STACK
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_VIRT_CPU_ACCOUNTING

arch/powerpc/kernel/stacktrace.c

@@ -88,7 +88,6 @@ save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
 }
 EXPORT_SYMBOL_GPL(save_stack_trace_regs);
 
-#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE
 /*
  * This function returns an error if it detects any unreliable features of the
  * stack.  Otherwise it guarantees that the stack trace is reliable.
@@ -220,7 +219,6 @@ int save_stack_trace_tsk_reliable(struct task_struct *tsk,
 
 	return ret;
 }
-#endif /* CONFIG_HAVE_RELIABLE_STACKTRACE */
 
 #if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_NMI_IPI)
 static void handle_backtrace_ipi(struct pt_regs *regs)