bpftool: Add missing link types

Will display the link type names in bpftool link show output
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220331154555.422506-3-milan@mdaverde.com

tools/bpf/bpftool/link.c

@@ -20,6 +20,9 @@ static const char * const link_type_name[] = {
 	[BPF_LINK_TYPE_CGROUP]			= "cgroup",
 	[BPF_LINK_TYPE_ITER]			= "iter",
 	[BPF_LINK_TYPE_NETNS]			= "netns",
+	[BPF_LINK_TYPE_XDP]			= "xdp",
+	[BPF_LINK_TYPE_PERF_EVENT]		= "perf_event",
+	[BPF_LINK_TYPE_KPROBE_MULTI]		= "kprobe_multi",
 };
 
 static struct hashmap *link_table;