ANDROID: arm64: stacktrace: Export arch_stack_walk symbol

The current dump_backtrace() will directly dump stack info to kernel
log, but in some cases, we need to save stack info in reserved buffer
to keep it clean and avoid being overwritten. Export arch_stack_walk
symbol to allow vendor modules to dump stack with customized function
to redirect and format the output.

Bug: 320201516
Change-Id: If883ba689724a8f1850d6cc925e06593be7884ed
Signed-off-by: Huang Yiwei <quic_hyiwei@quicinc.com>
Signed-off-by: Unnathi Chalicheemala <quic_uchalich@quicinc.com>

arch/arm64/kernel/stacktrace.c

@@ -293,6 +293,7 @@ noinline noinstr void arch_bpf_stack_walk(bool (*consume_entry)(void *cookie, u6
 
 	kunwind_stack_walk(arch_bpf_unwind_consume_entry, &data, current, NULL);
 }
+EXPORT_SYMBOL_GPL(arch_stack_walk);
 
 static bool dump_backtrace_entry(void *arg, unsigned long where)
 {