tc: add canid ematch to ematch_map

The canid ematch has been added in commit:

7b5f30e1 Ematch used to classify CAN frames according to their identifiers

But the corresponding entry in etc/iproute2/ematch_map was lost. This patch
adds the missing entry in ematch_map, otherweise tc would complain:

Error: Unable to find ematch "canid" in /etc/iproute2/ematch_map
Please assign a unique ID to the ematch kind the suggested entry is:
        7       canid
Signed-off-by: Rostislav Lisovy <lisovy@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

etc/iproute2/ematch_map

@@ -3,4 +3,5 @@
 2	nbyte
 3	u32
 4	meta
+7	canid
 8	ipset