Documentation: tracing: add new type '%pd' and '%pD' for kprobe

Similar to printk() '%pd' is for fetch dentry's name from struct dentry's
pointer, and '%pD' is for fetch file's name from struct file's pointer.

Link: https://lore.kernel.org/all/20240322064308.284457-4-yebin10@huawei.com/



Signed-off-by: Ye Bin <yebin10@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>