udp_diag: Wire the udp_diag module into kbuild

Copy-s/tcp/udp/-paste from TCP bits.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/Kconfig

@@ -409,6 +409,10 @@ config INET_TCP_DIAG
 	depends on INET_DIAG
 	def_tristate INET_DIAG
 
+config INET_UDP_DIAG
+	depends on INET_DIAG
+	def_tristate INET_DIAG
+
 menuconfig TCP_CONG_ADVANCED
 	bool "TCP: advanced congestion control"
 	---help---