arm64: Mark start_backtrace() notrace and NOKPROBE_SYMBOL

Mark the start_backtrace() as notrace and NOKPROBE_SYMBOL
because this function is called from ftrace and lockdep to
get the caller address via return_address(). The lockdep
is used in kprobes, it should also be NOKPROBE_SYMBOL.

Fixes: b07f3499

 ("arm64: stacktrace: Move start_backtrace() out of the header")
Cc: <stable@vger.kernel.org> # 5.13.x
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/164301227374.1433152.12808232644267107415.stgit@devnote2
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>